Weird Tics - the strange stuff we do without realizing it

I almost exclusively sit in seiza position with my legs under my thighs. I'm pretty sure it's just because I was short as a kid and did it to reach the table, and also real short still. But it's kind of weird because I can't get comfortable sitting on my ass, I'm always sitting on my legs all the time and just kind of naturally end up that way without thinking.