A guy walks into a bar in the Empire State Building. He orders a huge beer, chugs it, walkes over to the window, and jumps out. Five minutes later, the same guy walks back into the bar, orders another huge beer, chugs it, walkes over to the window, and jumps out again. Five minutes later, he reappears and repeats the whole thing.
At this point, another guy stops him and says, "Hey, how the hell did you do that?"
"It's just simple physics. When you chug the beer fast enough and the rest of your body is already warm, the warm air rises. And if the relative humidity and altitude are right and you hold your breath, you actually become lighter than air. Add that to the wind already swirling around outside the building, and you just float in the air."
"Wow!" exclaims the second man. "That's awesome! I gotta try that!" So he orders a huge beer, chugs it, goes over to the window, steps out, and lands -SPLAT!- on the sidewalk below.
The bartender looks over at the first man and says, "You know something, Superman? You're an asshole when you're drunk!"