Keira Knightley works hard to convince herself she is ''not s**t.''

The 'Anna Karenina' actress says she took a ''massive slamming'' earlier in her career which has had a permanent negative effect on her self-confidence.

In an interview in the new issue of Empire magazine, she said: ''When you take a massive slamming early on, I don't think you ever really get over it. I look at some actors of my age who didn't go through a slamming and I cannot understand the confidence. They're like a different species. I think that's ingrained into me now, that feeling of needing to convince myself I'm not s**t.''

Keira got her first big break in 'Bend It Like Beckham' in 2002 when she was just 17, but didn't feel like she was treated like a proper actress until after 'Pride And Prejudice' in 2005. Although she claims she never reads stories about her, she does sometimes get exposed to headlines.

The 27-year-old star - who is engaged to Klaxons musician James Righton - added: ''One 'Pirates Of The Caribbean' and a 'King Arthur' in and you realise the extent of what's being written. I so see stuff, it's amazing how many times you can go to a hairdresser and someone will show you an article saying you're an ugly, anorexic, talentless b***h and say, 'Isn't this amazing?' So you do become aware of things, but I stopped looking at about 19 or 20.''