“Sort of. Your body doesn't have a specific shape, and it doesn't have any rigid parts except for bones. If you want to say things stop after some motion, you have to say they stop relative to something else in particular, and the only way to do that that doesn't lead to hurting yourself or being unable to move is "this part of your body can only move so much relative to the part right next to it" — when I say part I mean like this patch of skin and the patch of skin next to it — and the result you get when you do that all over and smoothly is what I called a gentle reinforcement. It still makes you really tough, but if you did just that and tried to hit the sand like I did, you'd bend and flop instead of smashing the sand. You'd still be safe.”