"I wish I was Sienna Miller. I watch that girl and she’s fabulous. She talks to everyone and laughs and smiles. When I talk to her, I hope a bit of her party personality will rub off on me but it never does."

The Pirates Of The Caribbean star added that she also feels out of place on the red carpet.

"I’ve become phobic about the red carpet because you just get so scrutinised and all I think is, I’m going to be in the Top 10 worst dressed list tomorrow.

"I try, I really do, but I’m just no good at that stuff," she sighed.

I want to get a life, says Keira - May 2 2007
Keira Knightley has revealed she wants to quit acting, saying: "I want a life instead."

The 22-year-old Pirates Of The Caribbean star said the pressures of fame have become too much.

And she’s "devastated" at becoming a poster girl for anorexia because of her slender frame.

Speaking to Elle magazine, Keira said of her career: "The celebrity thing is completely crazy. I think I just have to move away or give it up altogether.

"I couldn’t have kids in the situation I’m in now. But I could just do something else. That’s probably what’s going to happen. I’m just not so hungry any more. I made a decision very recently that I wanted a life instead."

Keira reached her decision after a trekking holiday in the Himalayas.

"I spent 10 days in a place where no-one knew me or cared what films I’d been in," she said. "I got to have some total peace and balance and see myself as a tiny insignificant speck - something I really needed."

The actress spoke of her upset over pictures of her appearing on pro-anorexia websites.

Keira said the "physically gruelling" schedule for Pirates had caused her to lose weight.

She eventually asked the doctor how to become a size 12 - but he told her she’d have to eat unhealthy food and stop exercising.

"Basically, my body type is naturally thin. There’s nothing I can do about it," she said, adding: "I hate the fact that naturally thin women like me are becoming scapegoats for promoting a mental illness."

Nudity no problem for Keira - April 23 2007
Keira Knightley has revealed she enjoys stripping off for the camera because she finds sex scenes "liberating".

The gorgeous 22-year-old was just 16 when she had her first nude scenes, in 2001’s The Hole, and also had to bare her breasts while playing bounty hunter Domino Harvey in 2005.

But she told Sunday magazine: "Sex scenes are easy. I don’t really have a problem with them."

In fact, it seems Keira rather enjoyed the experience with Domino co-star Edgar Ramirez.

"Actually it was quite liberating in the movie Domino to be out in the middle of the desert, completely topless, with a beautiful Venezuelan guy. I was very lucky."

However liberating she found it, it seems the actress isn’t entirely happy with her body. The Pirates Of The Caribbean star, who has attracted criticism for her waif-like frame, confirmed she had a derriere double for Domino’s lapdancing scene.

She admitted: "I did have a body double for my bum. But not on my top. I don’t have a problem with that."

More woes for Keira - April 17 2007
The problems just keep coming for Keira Knightley, it seems.

Last week the 22-year-old actress told how she lives in fear of stalkers at home, and now she’s apparently complaining of loneliness while filming abroad.