A guy walks into a bar and sits down next to another guy slumped over the bar drunk.
The guy sits up and in a drunken slur goes...
"Did you know on a day like today, the winds between the buildings upwell so much, that when you jump off the roof you will float?"
The sober guy says there is no way...so up to the roof they go.
Sure enough, the drunk jumps off the roof, floats in the air, and then comes back over to the roof.
The sober guy goes "That's amazing!" and jumps off the roof and falls to his death.
The drunk walks back down into the bar, and the bartender, having witnessed the sober man fall through the front window, looked at the drunk and said "Ya know Superman, you can be a really A**hole when you're drunk."