Three guys are in a bar on the top of a cliff.
The first guy says to the other guys
"You know, if had just one more beer, I reckon I could fly."
The second guy says "No Way!"
So the first guy orders a beer and drinks it. Then all three guys walk out to the edge of the cliff. The first guy jumps off, starts falling to the ground, and then flies gracefully back to the top of the cliff.
The second guy is totally amazed, so he says
"You know, if I had another beer, I bet I could do that too."
All three guys go into the bar, and the second guy has one more beer.
After he finishes, he says
"Ok, I will be able to fly now."
All three of them go outside and the second guy jumps off of the cliff.
He falls to the bottom, hitting the ground and dying instantly.
The third guy turns to the first guy and said
"You know Superman, you can be a real jerk when you drink."