Sir Michael Caine didn't become an actor to be famous.

The 85-year-old actor has written a new memoir 'Blowing the Bloody Doors Off - And Other Lessons in Life' and he says one part of the book acts as a lesson to young people not to embark on an acting career in order to become ''rich and famous'' but because they have a passion for the craft.

In an interview on UK station BBC Radio 2, he said: ''I was watching the television and a man was interviewing young people about their futures and they were saying, 'I'm gonna do this,' and I noticed about half a dozen of them said, 'I want to be rich and famous'. But I thought that was entirely the wrong way to look at it, because in those days [when I started out] there were no thick cockney accents in plays believe me. I became an actor not to be rich and famous I became an actor knowing that I would never be rich a famous.''

Caine has gone to have a career that has spanned seven decades and has brought him wealth and fame due to his performances on the big screen.

The 'Zulu' star believes he owes his success to his passion for acting and his vow to never compare himself to anyone else in the business.

He said: ''The reason I became an actor is because I wanted to do and I wanted to be the best actor I could possibly be without reference to anyone else. There's always going to be someone better at what you do or worse at what you do and you wind up conceited or depressed.''