I have noticed that I am a rocker too. I don't know when I do it, I usually just catch myself. It's a comfort measure that I guess is as habit as me biting my nails, or someone cracking their fingers, etc. Sorry it's annoying the hubby but hopefully he can let you know gently when you are doing it (light tap on the knee, etc.) so you can catch it to be more aware of it and stop it. I actually don't mind the rocking. I know it makes me look a little "crazy" but I don't often do it in public, just when i'm lost in my head. There could be worse things.