My enginerd head has been trying get itself around pump tracks.
As in, conservation of energy laws - you have to put energy in, somehow, to keep the bike rolling, and it's obviously not by way of the cranks. It's magical.
I'm not there yet, just getting started. Wonderful brain food for those 3 am can't-sleep sessions. With luck I'll eventually dispel the magicality and turn it into something logical and boring in my mind, but probably I'll just let it stay there and not kill the magic for everyone else. It looks so zen. But I don't know the first thing about it.
As for the kid, he's got some crazy shit burned into his psyche. Doesn't stand a chance of being "normal". Good for him.