Isn't that strange? I would have never thought anyone else did that, I thought that it was my own quirky habit.

WOW! I don't believe it, I'm not alone here!

I do this, too! Except I usually have a fragment of a song in my head. I usually tap 4 fingers, then the next 4, etc. until every finger has had a turn starting the pattern. I also do this with my big toes!!!