Bill Murray has done "a lot of stupid things" because of his fame

He told The Sunday Times: "You have to have an ego to work with. You need it to get the work done.

"It's not important to try to change your ego, or to keep it in check, or dial it down. What's important is to watch it.

"Your first brush with fame - it's not like it got any bigger, but you lose control for a year or two.

"You make a lot of mistakes, you do a lot of stupid things, and you allow people to fluff you up."

Meanwhile, away from his movie career, the The Phoenician Scheme star has teamed up with his friend and celebrated cellist Jan Vogler for a tour that explores American values in literature and music, but Bill joked that he often starts every performance witha sense that he has got "absolutely nothing" to say before they go on stage.

He said: "He showed up in a pair of shorts and a T-shirt looking like he thought we were maybe going to throw rocks at buses.

"Right before we start every night I look at Jan and go, 'I've got absolutely nothing. I have no interest, no will, no desire. It's always that way. Do I really have to do this?

"It's becoming more clear that being a sloppy, flabby kind of a movie guy, just waiting around for someone to ask me to do a job ... I got a little lazy.

"Of late, people suggest things and I just say yes."