Brad Pitt is the only person to have successfully pranked George Clooney.
The Ides of March actor is known for playing tricks on his co-star, and despite many of his showbiz friends being equally enthusiastic about jokes, only the Moneyball star has succeeded in annoying his pal with a gag.
Matt Damon explained: "I've never gotten George. The thing is, George is a pro. He's very tough to get. He's got all of them down, he's very, very funny.
"The best one I saw on George was on Ocean's Twelve when Brad had a fake memo translated and given to the Italian crew. It was this whole thing saying, 'Please do not look Mr Clooney in the eye, only refer to him as Mr Ocean or Danny.'
"It was so the opposite of George that he was mortified when he found out, he was not happy about it. So that was the one time I saw someone get him."
Matt refuses to take himself seriously and doesn't mind if his friends poke fun if he appears in a flop movie.
He added in an interview with Shortlist magazine: "Even the movies that don't work you still work really hard on, so it's disappointing at first.
"But once you get past the disappointment of all that hard work not really going to a productive place, then you can mercilessly make fun of each other."
- BANG! Showbiz