1 – Jim Carrey – How the Grinch Stole Christmas
The elaborate costume and makeup Jim Carrey had to wear during the filming of How the Grinch Stole Christmas was so brutally uncomfortable that after his first day of filming, he told the director he couldn’t be in the movie.

Producer Brian Grazer was able to convince Carrey to stay by hiring an unexpected on-set expert, whom the actor described as a “gentleman who is trained to teach CIA operatives how to endure torture.” The anti-torture consultant advised Carrey to eat often, distract himself with television, ask someone to smack him when he was spiraling, and smoke a frankly un-Grinch-like amount of cigarettes.
2 – Emma Watson – Harry Potter and the Order of the Phoenix
Emma Watson considered leaving the Harry Potter franchise and her role as Hermione Granger behind before filming began on the fifth movie, Harry Potter and the Order of the Phoenix.

She claimed that the “fame thing had finally hit home in a big way” as the reason for her hesitation, but added that “no one had to convince me to see it through.” Said Watson, “The fans genuinely wanted us to succeed, and we all genuinely had each other’s backs. How great is that?”
3 – Nicole Kidman – Being the Ricardos
Nicole Kidman wanted to abandon the set of Being the Ricardos after there was backlash against her being cast as Lucille Ball. During an appearance on Live With Kelly and Ryan, Kidman said, “When the, sort of, the reality of playing her hit me, I went, ‘What have I said yes to?’ To which I then went, ‘Oh no, I’m not right, everyone thinks I’m not right, so I’m going to try to sidestep this.'”

But director Aaron Sorkin told her she couldn’t leave the role. According to Jezebel, Kidman said during a screening that she sent Sorkin an email that said, “I think I’m actually the wrong person now. I know I said ‘yes,’ but I’m now saying ‘no.’” But Sorkin replied, “You don’t get to say ‘no’ now!” The actor said she was “really glad that he pushed me.”
4 – Mark Ruffalo – 13 Going on 30
During an appearance on “Texting With” Instagram series, Jennifer Garner recalled that her co-star Mark Ruffalo almost quit 13 Going on 30 because he hated rehearsing for the “Thriller” dance scene.

Garner said, “Our first rehearsal, I think it was like Mark, Judy [Greer], and me, and Judy and I were both dancers growing up, and poor Mark didn’t know that. And he came in and hated the rehearsal process so much, he almost dropped out of the movie.”
5 – Ian McKellen – The Hobbit: An Unexpected Journey
In The Hobbit: An Unexpected Journey, Ian McKellen’s character Gandalf was supposed to be much taller than the other fantastical creatures.

To achieve this effect, McKellen had to film many of his scenes alone in front of a green screen, an isolating experience that led the actor to not only consider leaving the film, but acting altogether.