I bet if we all videoed ourselves for a day we would be suprised how much we move about and fidget when we think we are sitting or lying still. My wife often says to me, why are you rubbing your leg, why cant you stop tapping your fingers and just sit still. I get out of the chair to make a cup of tea even if I dont want one just so it looks like I'm moving about for a reason. I think this is due to a couple of things, anxiety and the over alertness we suffer, our minds are constantly on the lookout for danger so we find it hard to just sit quietly and wind down