Two men drinking at a rooftop bar on a skyscraper. One of them says to the other, "You know, the air currents around this place are amazing. You can step off the roof and just float."
"Yeah, right," the second guy says.
"Watch." And the first guy puts his beer down, walks to the edge of the roof, steps off, and, true to his word, floats around for a good thirty seconds before drifting back to the roof.
"Wow!" The second guy says. "I gotta try that!" He puts his own beer down, steps off the edge of the building, and plummets forty stories, screaming all the way.
The first guy grins, comes back to the bar, and quickly downs both beers as the bartender says, "You know, you're a mean drunk, Superman."
Rob