One day, a man went to a store and saw a sign that said "We Sell Everything, Guaranteed!" Intrigued, he decided to enter the store and test out their claim.
He walked up to the cashier and asked for a map of the world. The cashier reached under the counter and pulled out a tiny map, no bigger than a postage stamp. The man laughed and said, "I asked for a map of the world, not a map of a postage stamp!" The cashier replied, "Well, this is a map of the world. It's just to scale."
Undeterred, the man asked for a piece of rope. The cashier handed him a piece of rope that seemed impossibly short. The man exclaimed, "This is ridiculous! I asked for a piece of rope, not a piece of dental floss!" The cashier smiled and said, "Well, that's our guarantee – we sell everything, no matter how small."
Feeling defeated, the man decided to test the store one last time. He asked for a joke that would make him laugh for days. The cashier thought for a moment and then handed him a piece of paper with a single word written on it: "Your reflection."
Confused, the man looked at his reflection in the store's mirror and burst out laughing. He realized that the joke was on him the whole time, and left the store chuckling to himself. And so, the store's claim was proven true – they really did sell everything, even jokes at the customer's expense.