I can freak people out with my double-jointed thumb. It bends backwards completely in half. I never met anyone with a thumb like mine until two other professional musicians, also pianists, and I were showing off silly things we can do. I thought they'd marvel at my thumb, or at least say, "OOOOO, yuck!" but they showed me their double - jointed thumbs also! I can also hum and whistle at the same time and fold my hands behind my back (like the Praying Hands).
What silly trick can you do? There's a great "trick" you can use on adults or children, Have them fold their hands with their fingers curled down. Ask them to put their index fingers straight up. Tell them,
"Don't help me and don't fight me." Then use both your hands, one on each side of each index finger. Make screwing motions with your fingers, and say over and over, "I'm screwing your fingers together; I'm screwing your fingers together." Keep saying it until their fingers are together. If it doesn't happen gradually and start immediately, they're cheating; they're fighting you. This trick has a logical reason to work. Try it; if you can't figure it out, I'll tell you later. Just post.
What silly trick can you do? There's a great "trick" you can use on adults or children, Have them fold their hands with their fingers curled down. Ask them to put their index fingers straight up. Tell them,
"Don't help me and don't fight me." Then use both your hands, one on each side of each index finger. Make screwing motions with your fingers, and say over and over, "I'm screwing your fingers together; I'm screwing your fingers together." Keep saying it until their fingers are together. If it doesn't happen gradually and start immediately, they're cheating; they're fighting you. This trick has a logical reason to work. Try it; if you can't figure it out, I'll tell you later. Just post.