Brad Pitt and George Clooney are so down to earth a visiting alien wouldn't be able to tell them apart from regular people, according to pal Matt Damon. Damon insists he and his Ocean's Thirteen co-stars have formed such a close friendship, because Clooney and Pitt are no different to the friends he grew up with. Damon says, "George and Brad are kindred spirits. Having a beer with those two guys is like having a drink with guys I grew up with. It's just like any other group - cards, pool and a few beers. Behind closed doors you'd have no idea they were stars. "I'd love it if an alien came down for those two, and they were in a room with other guys, because they wouldn't be able to pick out the stars based on the way they behave."