Idiosyncrasy

I have a little secret. When I'm lying in bed, tired, but I can't sleep, I have a strange little idiosyncratic behavior. I "tickle" my arms by lightly running my fingernails up and down them. Strange, huh? No idea where I came up with it, been doing it since I can remember. But here's the strangest part..... .....HL does it too! I'm fairly certain he's never seen me do it- I only do it when I'm falling asleep in my own bed. Apparently it's a congenital idiosyncrasy. I expect my children to learn from my actions, but I was shocked by this.