A head rolls into a bar.
It says to the guy sitting at the bar, "Hey bud, can you put me up on the bar?"
So the guy picks the head up and puts it on the bar. The head says to the bartender, "Gimme a beer with a straw in it!"
So the bartender gives the head the drink and the head drinks it down. Suddenly he grows two arms.
The head says, "Wow! This beer works magic, gimme another!"
So the bartender gives him another drink, he drinks it down and grows two legs, and he says "Holy cow! now I have a full body!! Gimme another!"
The bartender complies, he drinks it, and explodes!
The moral of the story: Quit while your ahead.