Two guys are sitting in a bar on the top floor of a skyscraper. one guy turns to the other and says, "I'll bet you $100 I can ump out that window, float for thirty seconds, and climb back in without falling."
"That's impossible," the other guy says. "You're on."
The bartender stops to watch as the two guys approach the window. the guy who made the bet opens the window and climbs out. Sure enough, he floats for thirty seconds without falling, and then climbs back in. He demands his $100.
The other guy is stunned. "Double or nothing says if you can do it, I can, too!"
"You're on!" the first guy agrees.
The second guy climbs out the window and plummets forty stories to his death. The first guy quietly walks back to the bar and orders another drink. The bartender hands him his drink and says, "You sure are mean when you're drunk, Superman."