This is why some actors go insane lengths to stay in character. We've talked before about some of the craziest things actors have done to prepare for famous roles, but there's just so much crazy in this well we had to dip back into it.

30. Robert De Niro

Robert De Niro has done a number of admirable but totally unnecessary things to prepare for his roles, including working an entire month as a cab driver for Taxi Driver. To get ready for his role as Vito Corleone in The Godfather: Part II, he spent several months living in Sicily. He even learned how to play the saxophone for New York, New York, and now we can't stop thinking about Travis Bickle wailing on a sax. But that's not the craziest thing he's done.

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Image via Universal Pictures

For the chilling drama The Deer Hunter, De Niro insisted that a real, actual bullet be placed in the gun during the famous Russian roulette sequence. The bullet was taken out of the gun before the trigger was actually pulled, but that's... a work hazard, to say the least.

29. Kate Winslet

We've talked about the lengths Kate Winslet went to in order to took on the role of Hanna Schmitz for The Reader -- ultimately landing her the Academy Award for Best Actress. But that's nothing compared to what she did for her breakout role.

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Image via Paramount Pictures

Hard as it is to imagine, Winselt used to be a relative nobody, which was the case when she essentially stalked director James Cameron to convince him to cast her as Rose in Titanic. She found his private number and called him while he was driving on the freeway to lobby for the part, and sent him a pile of roses with the note "From your Rose." Of course, like many actors, she later vowed to never work with Cameron again, because he is also a maniac.

28. Johnny Depp

Johnny Depp is many, many things, and one of those things is "bizarre madman." We've already talked about the decidedly unsafe things he did to prepare for his role in Fear and Loathing in Las Vegas, but did you know he based his performance in Edward Scissorhands on his childhood dog?

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Image via 20th Century Fox

We can actually kind of see it, to be honest. He's made other equally strange choices in his career, including mimicking Michael Jackson in his role as Willy Wonka in Charlie and the Chocolate Factory, and basing his speech patterns and movement as Captain Jack Sparrow on Keith Richards.

27. Jamie Dornan

Just imagine yourself getting off at a subway stop, walking to your apartment or job, and then realizing several blocks later that someone is following you. Now imagine also realizing that the person following you is Christian Grey. Or even worse, the dude from that terrible new Robin Hood movie, making an extremely creepy effort to get inside the head of a character.

What we’re trying to say here is that Jamie Dornan totally admitted to stalking a woman on the street to prepare for his serial killer role in The Fall. He followed her off the London underground and for several blocks, later noting that it “felt kind of exciting, in a really sort of dirty way”. Accounting for the aforementioned Robin Hood movie, this has to be the second-most terrible thing he’s ever done.

26. Shia LaBeouf

While certainly an underrated actor, one of the least-surprising facts about Shia LaBeouf is that he goes insufferable lengths to get into a role. We've previously discussed many delightful examples, but we'd like to go into a little more detail about that time he filmed himself on acid and then made his friends watch the video.

According to the actor himself, while preparing for The Necessary Death of Charlie Countryman it occurred to him that he’d never tried LSD before. And so since he was playing a character who trips on acid, he did the only logical thing and tried acid for real. Then he filmed it and sent it to his co-stars for pointers and general feedback. Because that’s clearly how acting works.

25. Jared Leto

Undoubtedly the worst form of over-the-top method acting is the kind that a) makes you look like an ass, and b) was for a terrible film. We've already shared some of the stories of Jared Leto’s Joker-prep for Suicide Squad, in which the actor famously tormented his co-workers for the sake of a half-written and pandering story. But there's so much more.

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Image via Warner Bros.

Along with making everyone call him “Joker” on set, the actor claims he sent his costars “used condoms," an act which never improves any working relationship. The condoms were later clarified by director David Ayer as being “used” in the sense of being “taken out of the packaging” -- making him the annoyed parent to Leto’s edgelord teen.

24. Halle Berry

While male actors get the most buzz for insane method decisions, it’s important to remember that actresses not only a) bury themselves in their roles… but also b) are more than capable of annoying their friends and family in doing so. Halle Berry did just that back in the 90s for Spike Lee’s Jungle Fever.

When tasked with playing a crackhead for the film, Berry opted to forego bathing for roughly eight weeks -- describing the results as “gnarly”. We can’t disagree with that assessment, but are thankful she didn’t go any further than that when diving into the mind of a drug addict.

23. The Cast of 'One Flew Over The Cuckoo’s Nest'

Considering the methods described in this list, it sure doesn’t seem like actors need much preparation for getting in the minds of the mentally troubled. That didn’t stop the cast of One Flew Over The Cuckoo’s Nest from going the extra mile and opting to spend most of their days at the Oregon State Mental Hospital.

Turns out that, along with being the subject of the novel, this specific hospital agreed to be the shooting location for the film while maintaining its actual operations -- allowing the crew to use actual patients as extras. Considering what this film is about, the fact that any hospital would agree to this is either really brave or really stupid.

22. Angelina Jolie

The real life Gia Carangi struggled with drug addiction and isolation, making it less-than-ideal to completely method your way through her portrayal. Angelina Jolie settled on meeting the goal halfway, hoping that the role (which she felt personally connected to) would “purge her demons” in the process.

To fully realize her character’s loneliness, the actress cut off ties with her friends and even refrained from speaking to her then-husband Jonny Lee Miller, telling him “I’m alone; I’m dying; I’m gay; I’m not going to see you for weeks.” Pretty hardcore, but also suspicious since they divorced soon after this movie.

21. Margot Robbie

Before you ask: no, they didn’t make Margot Robbie perform all of the complicated ice skating tricks for I, Tonya but rather put her face on a double for a lot of the film. After all, it’s not a great idea to fling your leading actress over rock-hard ice while wearing knife shoes. It’s not really a great idea for anyone to do that.

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Image via 30West

With that said -- Robbie made the effort to do as much of the skating as she was allowed, often appearing in 30-40 seconds of each sequence. And she accomplished this by actually learning to skate -- training a good five days a week for four hours a day. That’s twenty exhausting hours a week!

20. Robert Pattinson

No offense, but this Batman-to-be already looks like the type of shady scruff to sleep in his clothes in a dirty basement. But when it came time to play a scumbag bank robber for Good Time, the actor did just that -- spending two months as a shut-in dwelling in a basement apartment.

Along with living like a sewer-dweller, Robert Pattinson never opened his curtains, didn’t change his sheets, and slept in his clothes -- keeping such odd hours that he managed to freak out his neighbors. At least that’s what he thinks. It’s possible they simply were afraid of vampires.

19. Chloë Sevigny

After breaking out in the Oscar-winning Boys Don't Cry, Chloë Sevigny accepted an oft-criticized role in The Brown Bunny which involved her performing an actual sex act with her then-boyfriend and director of the film Vincent Gallo. Still, it’s no surprise that this choice shocked many, including some of the cast.

There’s nothing wrong with performing a consensual sex act on film, and critics have since reevaluated their opinion of Sevigny's decision to accept the role. That said, it's kind of a shame that the movie involved Vincent Gallo, everyone's favorite insufferable film school student who famously put a curse on Roger Ebert for giving The Brown Bunny a negative review.

18. Tom Cruise

A good rule of thumb is that if Tom Cruise has weird-looking hair in a film, he’s likely going for an Oscar. Along with reminding us that he’s actually a good actor, Collateral is one of the rare instances where Cruise plays a bad guy. It’s also one of the neatest role preps on this list.

In an effort to realistically portray a trained killer, the actor not only received weapons training, but practiced going unnoticed in public. He did this by literally just going out in disguise, often as a delivery man, and hoping no one would realize he’s an international superstar. Luckily for him it worked!

17. Meryl Streep

Accents are tough. If an actor gets one wrong they can be ridiculed indefinitely. If they simply opt out of one, they can also be ridiculed -- sometimes even in Mel Brooks movies -- for their failure. Meryl Streep was aware of this fact (if not outright paranoid about it) when making Sophie’s Choice.

So since her character was meant to have a Polish accent, the actress opted to simply learn the entire language so as to not embarrass or offend anyone. Later she was surprised with the need to learn German as well, performing that language in the Polish accent. It’s almost as if she’s one of the best actors of her generation.

16. Linda Hamilton

As we prepare to be disappointed by the new Terminator sequel -- let us remember a time when the franchise was good with the story about Linda Hamilton clocking a man in the face. Specifically -- the man who played the evil orderly during her mental hospital scenes.

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After refusing to not pull his punches during a previous sequence, the actress grew so frustrated by having to perform a stunt multiple times that… when it came time for her to attack the actor… she did the exact opposite. This meant clubbing the poor man with a stunt nightstick.

15. Dwayne "The Rock" Johnson

A movie like the 2014 Hercules doesn’t really demand haunting levels of actor dedication in order to make back its $100 million dollar budget. If anything, it just needs to be fun and dumb enough to have one good opening weekend. It certainly didn’t require Dwayne "The Rock" Johnson to pass out from screaming.

And yet… that’s exactly what happened when it came to a scene in which the titular character attempts to break free of his chains. According to the actor himself, he requested actual metal chains to make his struggle real. And it was! Because he also blacked out all eight times he did the scene.

14. Nicole Kidman

If you ever wanted to be even more creeped out by John Cusack, The Paperboy is for you. Similarly, if you’ve ever fantasized about Nicole Kidman urinating on Zac Efron then you should also check out this film. And that’s probably the only two reasons to see this film.

In the movie, Efron is stung by a jellyfish and, believing a certain myth, is told that the best way to relieve the pain is to be peed on. That’s where Kidman comes in handy. And while there’s certainly a way to fake this stunt, they decided to go method and have the actress actually just do it for some reason.

13. Leonardo DiCaprio

Leonardo DiCaprio ate raw bison and slept inside animal carcasses like Luke Skywalker on the set of The Revenant, so it's no surprise he's willing to engage in some pretty intense stuff to prepare for his roles. In his breakout role as the mentally disabled Arnold in What's Eating Gilbert Grape, DiCaprio spent a few days living at a home for disabled teenagers, talking with the residents and observing how they interacted with each other.

For his role as an undercover cop in The Departed, DiCaprio met with several people in Boston with ties to the Irish mob and got swole, gaining 15 pounds of muscle. He really didn't want people thinking of him as "the Titanic kid" in this gritty crime drama.

12. Choi Min-sik

If you’ve seen the film Oldboy then you know exactly what scene we’re talking about. After escaping his 15-year prison sentence, Oh Dae-su enters a sushi restaurant and begins to devour a live octopus. We've mentioned this before, but there are some pretty intense details that make it worth revisiting.

For instance, what you might not know is that this took four octopuses to achieve, something that actor Choi Min-sik wasn’t too happy about considering that he is also a Buddhist. His solution was to say a prayer for the life he took with each take. But honestly the taste alone was probably atonement enough.

11. Forest Whitaker

We've talked about how Forest Whitaker gained a bunch of weight and learned to speak Swahili when he took on the lead role in The Last King Of Scotland, something that ultimately landed him the Best Actor Oscar (and for very good reason). Whitaker is known for doing extensive preparation for his films, including his first breakout lead role as Charlie Parker in the film Bird.

To get into character as the legendary jazz musician, Whitaker lived in a tiny loft with nothing but a couch, a bed, and a saxophone. He took lessons to learn how to play the instrument, even though all of the musical scenes in the film were performed by jazz soloist Charles McPherson. That's right - he lived with a saxophone and learned how to play it, even though the movie didn't require him to do so.

10. Dustin Hoffman

After his breakout role as a clean-cut college student in The Graduate, Dustin Hoffman was in danger of being typecast. So he disguised himself as a homeless person and met the director of Midnight Cowboy in Times Square to prove he could play darker characters.

Hoffman hung around the set of Hook for two months before he was actually required to be there, just to get immersed in the Neverland setting for his role as Captain Hook. And to prepare for his Oscar-winning role as Raymond in Rain Man, Hoffman spent a full two years befriending adults with autism in order to give an authentic and empathetic performance.

9. The Cast of 'The Blair Witch Project'

As countless found footage follow ups have proved: there’s never going to be a film quite like The Blair Witch Project ever again. While it wasn’t the first of its genre, what made the production unique was the pioneer viral marketing combined with an over-the-top devotion to siphoning the sanity of their actors.

The actors were stuck in the woods and given GPS devices, told where to go daily and given zero contact with the crew. And when it came time for their characters to run low on rations, the actors food was also taken away. In short: everything you see is pretty real (save for the presence of a mythical witch).

8. Steve Carell

While it continues to become more and more problematic with each passing year, there’s no denying the many careers that were boosted by The 40-Year-Old Virgin. And there’s at least one scene that remains respectable, and that’s of course the moment Steve Carell opted to wax his chest hair.

As you can probably guess by just watching the scene: this happened for real -- with Carell and his co-stars improving over his torment. Considering that they only had one shot at this (how long does chest hair take to regrow?) you can only imagine the pressure of being both a) funny and b) hoping your nipple doesn’t tear off.

7. Ryan Gosling and Michelle Williams

There are co-workers we can barely stand, let alone exist in the same house as. Let’s hope that wasn’t the case for Ryan Gosling and Michelle Williams when they made Blue Valentine -- a film that required the actors to remain totally immersed in playing a married couple.

To fully capture the intimacy, Gosling and Williams actually lived with each other for a month -- at least during the day -- in a household along with the actress playing their daughter. While that fine and good for the adult actors, it’s grim to imagine being given house chores by the dude from The Notebook.

6. Marlon Brando

There’s seriously only one excuse for impersonating a veteran, and that is to research an acting role. And even then, it’s a pretty sketchy thing to do. This is why it definitely helps if you are also Marlon Brando, a man who managed to get away with way too many acting shenanigans. We've previously mentioned some of the lengths Brando went to prepare for his debut role in The Men, but the details are so insane we had to share them.

Brando actually spent weeks in a VA hospital, assuming the identity of an actual veteran and even living as a paraplegic. Furthermore, he insisted on staying in his wheelchair both on and off set during the entire production. To avoid being a total ass, Brando did eventually let the real vets know his true identity, and took his new friends out on drinking adventures. Brando later claimed that his role in the film got him drafted during the Korean War, but that he got out of serving by providing totally insane answers on his psychiatric exam, a thing he might not have done on purpose.

5. Adrien Brody

We've already told you how Adrien Brody essentially gave up his entire life when preparing for his role in The Pianist, so it should come as no surprise that there's not much he isn't willing to do. For his role as a ventriloquist in Dummy, Brody learned both puppetry and ventriloquism to such an extensive degree that he was able to perform every ventriloquism scene live, with no vocal dubbing or professional stand-ins.

His aptitude for ventriloquism makes a ton of sense when you read about his role as Harry Houdini in the 2014 miniseries Houdini. Brody had studied stage magic extensively as a kid, and performed most of the magic-related stunts in the film, including a sequence wherein Houdini escapes from a strait jacket while hanging upside down.

4. Jamie Foxx

Jamie Foxx prepared for his role as the good-natured cab driver terrorized by a murderous assassin in Collateral by actually driving around as a cabbie, much like De Niro before him. For the scenes that required him to drive recklessly through the city to thwart the film's villain Vincent (Tom Cruise), Foxx practiced racing on a speedway in the Mohave Desert with director Michael Mann. Mann even provided detailed written backstories for Foxx and Cruise to study. This is way more work than most actors do for roles.

We previously mentioned the crazy preparation Foxx underwent for his role in The Soloist, but we left out the part where he got cosmetic surgery. Foxx actually had his teeth chiseled down to make him look more like a mentally ill homeless person and less like a handsome Hollywood actor. And nobody saw that movie.

3. Nicolas Cage

Society has long abandoned any attempt to understand the swirling spectrum of acting and inflection choices tucked within the vault of Nicolas Cage’s brain. He is truly the chaotic-neutral of actors, as evidenced by literally everything he has ever done. And on the commercial side of things, there’s Ghost Rider.

Image via Warner Bros.

While playing a character whose entire head was replaced by CGI, the actor insisted on being in full-makeup on set. Specifically, he wanted to look “like a Afro-Caribbean icon called Baron Samedi” in order to fully immerse himself in the character. This was, to be very clear, at the request of no one.

2. Joaquin Phoenix

Somewhere in the realm between Jared Leto and Daniel Day Lewis exists the acting choices of Joaquin Phoenix -- a man that isn’t quite insufferable when you consider his body of work. Like the aforementioned pair, he has enough moments to fill an entire list of examples.

But one of the craziest has to be when he made The Master, playing a man with such a deeply clenched jaw that he actually paid a dentist to brackets and rubber bands so that his teeth stayed shut. That’s still the second-wildest thing, right behind the time he sacrificed his entire career for committing to his "I'm quitting acting to be a rapper" bit in I'm Still Here.

1. Daniel Day-Lewis

We've already discussed some of the insane method choices of Daniel Day Lewis, it should come as zero surprise that he’s taking our number one spot on this list. The man is the Hulk Hogan of crazy acting, and could also probably play Hogan in a biopic.

Stories include: learning to speak Czech, building a canoe, learning to box, refusing to bathe, living in a shack, staying in character as Lincoln even while using his cellphone -- and worst of all: listening to a bunch of Eminem while preparing for Gangs Of New York.