British actress Keira Knightley hates watching herself on screen because she thinks she can't act.

The Pride And Prejudice beauty is her own worst critic and insists there's nothing more painful than watching her own performances.

She says, "I'm my biggest critic by a mile. You give me the worst review ever and times it by about 10 - that's where I put myself. It's a huge fault.

And Knightley is such a perfectionist she'd like the opportunity to re-make some of her films, including Pirates Of The Caribbean, whose third installment she is currently shooting.

She says, "It's really difficult to go back to a performance that I'd now like to do completely differently.

"Suddenly you think, 'Oh, I wish I hadn't done that and I wish she had been like this."