Cameron Diaz always wants to do movie sequels.

The 37-year-old actress confesses the roles she takes on represent certain times and she is always keen to return to characters because she feels she knows them.

She said: "You play characters at certain times in your life and you access the relevancy of that time in your life.

"I always want to go back and play characters again just because you understand them better. I always feel like I'm playing them before I understand them, but really what happens is you learn to understand the world better through your characters."

The 'Knight and Day' actress' co-star Tom Cruise also admits he was never confident about being in the business.

He told Empire Magazine: "I never had a problem waiting or bussing tables or digging a ditch and I've worked all those jobs. And I will work hard. So for me that's what I've always felt secure in. That gave me an inherent confidence.

"Being a movie star? I don't know. I never... I just always kind of looked at it like, 'I get to make another movie.' "