Actress Keira Knightley believes she must have coped with being famous because she has avoided becoming a drug addict, despite shooting to fame at a young age.

The 29-year-old shot to fame as a teenager in 2002 comedy-drama movie `Bend It Like Beckham`, and she feels grateful that she hasn't gone down the route of becoming addicted to illegal substances like some celebrities who became famous at an early age, reports contactmusic.com.

Speaking about her rise to fame, she said: "Luckily it was so long ago that I can't remember what it was like when it happened. But I'm still here, I'm still alive and I'm not a drug addict, so it must have been all right."

The `Begin Again` star is married to Klaxons vocalist James Righton and admits it seems a lot more common for young musicians than movie stars to become embroiled in a world of drugs because they live their lives as "extremely as they can".

"They very much walk that line. A lot live life as extremely as they can, and that's absolutely fascinating for so many people and has been since the beginning of time,` she said.

"We've been fascinated by youth that has absolutely no fear of anything and could corrupt and could die at any second. It's the moth-to-the-flame thing. So much of rock 'n' roll is about that,` added the actress, who has starred in "Pirates Of The Caribbean" series and "Pride & Prejudice".