This snail crawls up to this bar as it was closing. The snail pounds and pounds on the door until the bartender finally opens the door. The bartender looks around and sees nothing until the snail demands a beer. The bartender looks down and sees him, but replies, "Hey, we're closed now and besides we don't serve snails!" and proceeds to slam the door.
The snail again pounds on the door. The bartender becomes so frustrated that he opens the door again and kicks the snail away.
A year later as the bartender was about to close again, he hears a pounding on the door again. He opens the door and looks down to see the same snail again. The snail looked up and replies, "What'd you do that for?"