AceShowbiz - Keira Knightley struggled with playing "everybody's object of lust" in her teens. The "Pirates of the Caribbean" actress landed the role of aristocrat turned pirate Elizabeth Swann alongside Johnny Depp and Orlando Bloom in the swashbuckling franchise when she was 17 after her breakthrough role as a tomboy footballer in "Bend it Like Beckham", and said the role left her feeling "very stuck."

She told the April issue of Harper's Bazaar magazine about the part, "She was the object of everybody's lust. Not that she doesn't have a lot of fight in her. But it was interesting coming from being really tomboyish to getting projected as quite the opposite. I felt very constrained. I felt very stuck. So the roles afterwards were about trying to break out of that."

Keira added about starting acting early, "I had quite an entrance into adult life, an extreme landing because of the experience of fame at a very early age. There's a funny place where women are meant to sit, publicly, and I never felt comfortable with that. It was a big jolt... I was being judged on what I was projecting."

Keira, who has daughters Edie, seven, and four year old Delilah with her "Klaxons" musician husband James Righton, 39, added she thinks of 2003 to 2008 "a very tricky five-year window" in her career despite appearing in box office hits "Love Actually", "Pride and Prejudice" and "Atonement", as she felt "powerless." She added, "I didn't have a sense of how to articulate it. It very much felt like I was caged in a thing I didn't understand."

Keira also said about pushing herself to "burnout" in her youth by being consumed with desire to succeed in acting, "I was incredibly hard on myself. I was never good enough. I was utterly single-minded. I was so ambitious. I was so driven. I was always trying to get better and better and improve, which is an exhausting way to live your life. Exhausting. I am in awe of my 22 year old self, because I'd like a bit more of her back. And it's only by not being like that any longer that I realise how extraordinary it was. But it does have a cost... burnout." The April issue of Harper's Bazaar U.K. is on sale from March 9.