I used to be pretty badly obsessive, with strange patterns always imposing themselves. Everything had to be balanced, so something like folding my hands was irritating (because folding your hands breaks the left-right symmetry of the human body; either the left thumb is on top, or the right). I still have a lot of these tendencies -- just typing this, I have a compulsion to have my fingers rest in a particular symmetric way when I'm not typing a word.
This obsession with symmetry (as I would describe it) has actually been very helpful for things like programming (I never forget a semicolon, and my formatting and naming conventions are immaculate; I write the most readable code of anybody I know) and math (I never drop a negative sign or power of i).
It's a lot less intrusive on my thought process than it was when I was little, and I have come to deeply appreciate broken symmetries -- in fact, I've come to think that much of what we think of as beauty comes from symmetry breaking, whether in music or art or architecture or the natural environment -- or in quantum field theory! Perfect symmetries are trivial, but broken symmetries are endlessly intriguing.
