One of my new coworkers is a mutterer. Actually he's more of a singer-under-his-breath. This drives me nuts. It's a classic case of someone's habit bugging me because it's a more intense version of my own bad habits. I WANT to sing under my breath with no regard for the folks around me. I just don't. I keep it in my pants. We're crammed in too close to be letting our neurotic little tics run rampant.
In the privacy of my own home, though, I'm a muttering, singing, yammering fool. I just have the decency to confine my shuffling mental patient act behind closed doors. Weirdness is fine so long as it is contained. Your right to be neurotic stops where my touchy sensibilities begin, and vice versa.