A man drinks a shot of whiskey every night before bed. After years of this, the wife wants him to quit; she gets two shot glasses, filling one with water and the other with whiskey.
After getting him to the table that had the glasses, she brings his bait box. She says "I want you to see this." She puts a worm in the water, and it swims around.
She puts a worm in the whiskey, and the worm dies immediately. She then says, feeling that she has made her point clear, "What do you have to say about this experiment?"
He responds by saying: "If I drink whiskey, I won't get worms!"