Hathaway confirmed that rumor after Knocked Up was released, stating that she didn't feel comfortable being part of the move because she hadn't experienced motherhood firsthand. “I didn’t know how I was going to feel on the other side about giving birth,” said Hathaway when she was interviewed by Allure. After Hathaway pulled out, Katherine Heigl hopped in her place. Heigl later went on the record with Vanity Fair stating that the movie was "a little sexist."
Jennifer Hudson, Precious
In Jennifer Hudson’s 2012 autobiography I Got This: How I Changed My Ways and Lost What Weighed Me Down, she wrote that she had been offered the lead in Precious. She turned the role down, but why? Jennifer Hudson “wanted to try a role that had nothing to do whatsoever with [her] weight.”
The role of the protagonist ended up being played by Gabourey Sidibe. This was her first major role ever, and she received an Oscar nomination for it. Hudson ended up interviewing with the Huffington Post after Precious was released. She stated: “I just felt the character was doing things, at least in my script that I got, that were places I did not want to go and not where I needed to go.”
Will Smith, The Matrix
It has been said that an actor who does not know their own limits is an actor that shouldn't be hired. Will Smith knows this better than most. When Smith was offered the role of Neo, he was confused by how the movie was pitched to him. He didn't quite know how to act with a 360° camera.