My dad used to (and still does) amaze young and old with a trick whereby he would flip a coin on his wrist. I, too, was confounded by his prestidigitation and for many years could not perform the feat myself. Finally he showed me how it worked. But knowing how it worked and actually being able to do it are two very different things. It involves causing one tendon in your wrist to slide under another, then making it suddenly (and with sufficient force) pop out, causing the coin to flip. It took weeks of practice to finally get it to work. And when I did get it to work, my wrist was so sore I could barely get it to move.
I can do it with a quarter, Dad can do it with a silver dollar. The video below is using a token for a laundromat in Mons, Belgium (yes, I washed my skivvies in Belgium once upon a time). I get one of two reactions: “Ooh, how did you do that?” or “Eww, that’s gross”.
Now, I submit to you, The Wrist Coin Flip: