One night, a drunk man stumbled into a bar and announced to the bartender, "Drinks for everyone, on me—including you, bartender!" The bartender served the drinks and presented a bill for $36.50. The drunk admitted he had no money, so the bartender slapped him and threw him out.
The following night, the same drunk returned. He once again ordered drinks for everyone in the bar, including the bartender. The bartender complied, but when the drunk again claimed to have no money, he was slapped and thrown out as before.
On the third night, the drunk entered and declared, "Drinks all around—except for you, bartender!"
"What? No drink for me?" asked the bartender, surprised.
"No way," replied the drunk. "You get violent when you drink."