The one to your dumb friend... A guy sees an ad on the window of a store with the words "Selling brains". Curious, he walks in and asks the shopkeeper what kind of brains he's selling. Shopkeeper: "I've got Einstein's brain who won a Nobel Prize and discovered the Universe's secret equation. He was the world most brilhant physicist. I can sell it for 3k." Guy: "What about that one?" SK: " That's the brain of Galileu Galilei. He was the great astronomer who supported that the Earth revolves around the Sun. He was the father of modern science. It's worth 2k." Guy: "And what about that one?" SK: "That's the brain of [*random friend*] . It costs 20k." Guy: "20k?!? That's a lot! Why is it worth that much?" SK: "Well, it has never been used." Edit: Formatting