I'm kind of amazed at the advice out there for parents with auties. I mean amazed in the sense that a lot of it is obvious - at least to us. Some sites talk about stimming behaviours and how to work with them. They even have names for them. We just called them "Crazy time!"
I'm going to guess a lot of parents tried to stop their kids from doing these things, but we've learned from experience that when they are actively encouraged, they last less time or sometimes disappear completely. And I've always just assumed he was doing them because either he needed to or just plain liked it. Sure, it's best to figure out the underlying cause - sometimes they can do it because of pain, but sometimes he could just be bored. As long as he does things in a way that is safe, I don't think it really matters.
But it is sort of interesting to read that other kids do the same thing and to understand why he'll get all revved up before bedtime. (Auties lack the perception of social cues before bedtime, like dimming the lights, being quiet, so there's no point in doing those things with him - as we've already figured out on our own!) He likes to do what's called "crashing" - running or falling into objects (luckily, usually the bed or the couch, but sometimes the floor). Sometimes I feel like I should just live in a giant padded house.
I can deal with the hand flapping, except when he wants to share the experience and does it in my face - which is very nice and generous of him and I'm sure it's great for him, just not for me!
Since I put on the two twisty knobs in the kitchen, he's greatly reduced his spinning. Maybe partly because he can no longer get a rise out of me when doing it. Really, I am a patient mom with all the other weird behaviours, but him spinning my kitchen knobs just gets under my skin in the worst way.
I am just very much against stopping him from being him. He is quirky, he is different, but it's not something to be restrained. As far as I'm concerned, if it hurts no one and distracts no one, it's fine. I'm saying he should be able to control himself on a public bus or at school (he should not stop other kids from learning), but he should be free to do what he needs to do for self-stimulation at home or any other appropriate place. He takes me as I am. It only seems fair I take him as he is.