A man is sitting at home when he hears a knock on the door...

A man is sitting at home when he hears a knock on the door...

He opens the door and sees a snail sitting there on the porch. He picks up the snail, and throws it as far as he can.

Three years later, there's a knock on the door. The man opens the door. There sits the same snail.

The snail says, "Now what the hell was that all about?"