A guy hears a knocking on his door. He opens it up, and no one is there. He looks all around and he finally sees a little snail sitting on the doormat. He picks it up and throws it across the street into a field.

Ten years later, he hears a knocking on his door. He opens it up and no one is there. He looks all around, and he finally sees a little snail sitting on the doormat.

The snail says, 'What the heck was that all about?'