Hi everyone!
When I'm on my own, I hand flap, arm fling, grimace and pace every day. When I say pacing, I don't mean a steady walk - I hold my body in funny positions, fling my arms and hands around, and I can go from nought to a hundred in 1 second, as in one second I'll be walking and then suddenly I'll have leapt into a..well a leap forward with my arms flung out! I also rock backwards and forwards a lot.
I can't stop because this is how my body is set to be! Well, obviously I can stop myself pacing and moving my arms for short-medium periods, but I need to do it when I get home at the end of a long day, I couldn't stop for a week at a time or anything like that. To be honest I don't even notice when I start all the time - I frequently suddenly realise my face is already slightly screwed up for instance. Clearly I need this sensory input. It feels completely wrong to sit still for long periods - I can't without jiggling my ankle around really fast. It feels wrong and actually uncomfortable to not be pacing or moving my arms for any length of time, I get an uncomfortable sensation in my muscles in my arms and legs and back, which I can only ease by starting to move them around. And you know what? It not only feels right to pace etc, it feels frankly joyful at times. It's a wonderful sensation, really wonderful. You get totaly lost in it. I wouldn't want to live my life without these sensations.
The good news is that it feels amazing. The bad news for me is that despite how right it is for me, I feel really embarassed if anyone except my very close family see me doing it. I mentally say 'oh shit' when i realise I've screwed my face up and someone might have seen. One of my flatmates came into the kitchen and i was rocking backwards and forwards quite violently on the sofa, and I wanted the floow to swallow me up. She thought something was wrong, but she was fine with me saying I was fine and i did it all the time. Sometimes days at uni drag because all I want is to pace.
The other bad thing is when I bash my head against the wall while rocking - I'm paranoid about the edge of my bed now, because I'm going to end up in A&E bleeding and with a concussion if I actually smash the back of my head against it one day instead of 'just' hitting the wall above it (just an achey head from that). Oh and no one tell my dad that I may have loosened the sitting room lights where they're fixed into the ceiling by accidently smacking my hand against them really hard 
Funnily enough, all this repetetive movement has become really pronounced as I've got older, even as my issues with communication have become non-issues in some situations and only mildly problematic otherwise. I'm still not great at small talk, social chit chat, maintaining talking to the same person for long periods and a couple other things, but otherwise I present a totally different picture to the child diagnosed 14 years ago (I read the diagnosis letter again today -wow!), to the extent I study a subject involving lots of communication and don't struggle at all with that aspect.