I used to do this thing with my tongue where I would move it in pattern in my mouth. It was always 4 hits against my mouth, two top, two bottom, and then I would reverse it trying to make it even but then the pattern would just get bigger and bigger like a backwards fractal until my brain simply couldn't process that many numbers at once. At least I feel like I have a fairly clear idea of what my brain is capable of handling.

Here is a picture of my pattern. The first one is the pattern and the second is the order of the hits in my mouth. This is kind of hard to explain, but here are my diagrams: This random lines are so that they stay separated when I post. The second set of numbers is what I would do after the first one.

_ _ | 1 4 | 4 1
- - | 32 | 23

It would get really complex really quick. Hope that made sense; things like this are hard to explain to someone who doesn't already understand. I would do this with other items and actions as well though.

I tap my feet to that rhythm nonstop. I touch items on shelves at Wal-Mart in that pattern. It isn't too disruptive. Thankfully I can control it when I'm driving because there are so many other things for me to look at. Whenever I suppress the desire to make this pattern with things, I shiver uncontrollably for about 3 seconds and make a weird face because my muscles freak out. Not good for in bed...

If anyone understood this, please tell me.