Hmmm...
Like a load of people here, I hold imaginary conversations in my head with other people, imagining how certain conversations might go. If no one is around at home I've been known to hold my part of the conversation out loud.
I argue with myself sometimes. Its okay though, I've never lost an argument yet!
I near constantly have music going on in my head, or a rhythm or such like. I can often be found to have one part or another of my body moving in some kind of rhythmic pattern of some sorts. As I type my right foot is tapping against my left! Earlier at lunch, again whilst no one was around I was doing very complicated rhythms involving thigh slaps, hand claps and stomps of the feet, mixing in some obscure syncopated stuff, and at one stage I had my hands working on a 3/4 rhythm whilst the feet were doing 4/4, and then waited until they synced the first beat again before switching back.
If no one is around at home I'm often to be found singing loudly, and when I say loud, I mean loud
Years of training, choral singing and solo singing has meant I've got a very powerful voice. Whatever I do I can be found singing, sometimes trying all sorts of different ways to link two completely different songs together.
My strangest thing? I'll skip along a corridor at work if no one is watching. Sometimes I'll do it even if someone is watching. If I don't skip I'll sometimes double step or twice to the rhythm or song in my head at the time. A quick skip is absolutely guaranteed to bring a smile to your face. I've yet to see anyone really start to skip and not start smiling!
A few of my bizarre quirks and traits there for ya.