One day a man was sitting on his sofa at home when he heard a knock at the door. He got up to see who it was but when he opened the door no one was there. Just as he was about to sit down he heard the knock again but when he got there again, there was no one at the door.
He scratched his head, looked around for a second and looked down to see a tiny snail on the porch.
He picked up the snail, threw it into a field across the street and headed back inside to watch television again.
Three Years Later
The same man is sitting on his sofa watching TV and hears a knock at the door. He gets up and goes to see who`s there and there is no one.
He looks around for a second and just as he is about to close the door, he looks down and sees the snail who looks back up and says "What the Hell was that all about!!?".