11 of Actors' Toughest Roles: From Joaquin Phoenix's Joker to Daniel Day-Lewis' Reynolds Woodcock and More

"Because it was such a physical role, the echoes of it are still with me and I think I’m like a lot of audience members, I need time to process it. I’ve been trying to stop acting my entire professional life," said Cate Blanchett.

Separating himself from his role as serial killer Ted Bundy "was almost impossible. I’d like to say that I did it successfully, but I couldn’t," Zac Efron said.

Natalie Portman said, "It was the first time I understood how you could get so wrapped up in a role that it could sort of take you down. There were some nights that I thought I literally was going to die."

On dropping 52 pounds to play Joker, Joaquin Phoenix said, "What’s difficult is waking up every day and being obsessed over like 0.3 pounds. Right? And you really develop, like, a disorder. It affects your psychology. You start to go mad."

Jessica Alba said director Tim Story told her, "Can you be prettier when you cry? Cry pretty, Jessica."

The constant criticism made her ask herself, "Are my instincts and my emotions not good enough? I don’t care about this business anymore."

Working in claustrophobic, wet conditions, Robert Pattinson admitted, "That’s the closest I’ve come to punching a director. It was like some kind of torture. It definitely creates an interesting energy."

"I was in such a state of deprivation — physical and emotional. When I got home, I couldn’t react to the chaos of the world without being overwhelmed. It took me weeks till I felt like myself again," said Anne Hathaway.

Director Paul Thomas Anderson "and I laughed a lot before we made the movie. And then we stopped laughing because we were both overwhelmed by a sense of sadness. It was hard to live with. And still is," the actor said.

Daniel Day-Lewis quit acting after this movie. "The last day of shooting is surreal. Your mind, your body, your spirit are not prepared to accept that this experience is coming to an end," he shared.

"Right away the director did not want me in this movie and made it clear all the time," the handsome hunk said.

Asked to do a dangerous stunt, Freddie Prinze Jr. said, "It was so scary! I was like, ‘Yo, if this is how it’s going to be, I can’t handle this.’"

The Holocaust story really threw her, Kate Winslet said.

"I am still coming to terms with the whole experience. I really, genuinely am. It was truly overwhelming. I really went somewhere. I was in some kind of a trance. And I’m still coming to terms with all of it."

Still haunted by nightmares by his role, Jake Gyllenhaal said, "Physically, it showed itself, but chemically and mentally, I think it was even a more fascinating journey. It became a struggle for me."