An angry bartender was closing up for the night when he heard a knock at the
door. 

He opened the door, didn't see anybody, and was about to close the door when a
voice called, "Hey, down here." 

The bartender looked down and saw a snail.

"Hey," the snail asked, "how about a drink?" 

The angry bartender snarled, "First of all, we're closed. Secondly, we don't
serve snails." And with that, the bartender kicked the snail all the way across
the street.

A month later, the same angry bartender was closing up for the night when there
was a knock at the door. 

He opened the door, and there was the same snail from last month. 

"You know," the snail said, "you didn't have to kick me."