Bradley Cooper thought it was a joke when he was named the Sexiest Man Alive.

The Hangover actor explained that he thought he was being pranked when he took People magazine's annual title in 2011.

Speaking to the Daily Mail newspaper, Cooper said: ''They called, and I actually thought it was a joke. There's nothing in it at all. I mean, look at me!''

The Silver Linings Playbook star says he let fame go to his head when he first gained notoriety working on TV show Alias in 2001, but quickly managed to lose his big ego.

He added: ''I was 25, and there was something gratifying about someone you don't know, knowing you. The whole idea of fame could absolutely fill a void if you let it in. Luckily I was young.''

Channing Tatum is rumoured to have already been chosen as the sexiest guy of 2012.