Brian-
That is an excellent point..it's almost like a vicious cycle. You don't notice the twitches for awhile, then you remember that you don't notice them and then all of a sudden they are there! I find that like you when I am pre-occupied I notice them less but when I am sitting still or not doing much I notice them more. What;s interesting though is that when I am standing I hardly ever notice them even when I am thinking about it.
--David