The best-actress Oscar winner for "Silver Linings Playbook" tells the September issue of Vogue magazine that she used to "lie in bed and wonder" about what would make her well-known.
She says, "It wasn't a vision. But as it's kind of happening, you have this buried understanding: of course."
The 22-year-old also says her childhood was "unhappy" because she was "anxious" and her parents sent her to a therapist.
It was when she was cast in 2007 in the TV series "The Bill Engvall Show" that her mother realized she no longer needed counseling because when she was acting, it made her happy.
Vogue's September issue goes on sale Aug. 20.