The other day, I was writing with a ballpoint and realized I was rotating it slightly--sort of rolling it to the left--at the end of each line, or whenever I lifted my hand for a moment. It's something I do--something we all do, I assume--with wooden pencils without even thinking about it, so the point wears evenly, but it has no real purpose with pens except to sort of reseat your grip every so often. The only reason I noticed was because the clip on this particular pen kept getting in the way now and again, and I finally figured out it was coming around the rotation every so many lines and rubbing against my hand--until I rotated it away again.
I do this with mechanical pencils, too, to the point where when I picked up a Uni Kuru Toga pencil (which rotates the very point of the pencil for you to maintain a consistent point), we fought--because I couldn't break myself of the habit of turning the pencil, even though it was rotating for me.
Now...obviously I don't do this with fountain pens, or they'd stop working every time I got to the end of a line. So my subconscious apparently has it figured out that they're another species. Why, then, does it lump most other pens with pencils, I wonder?
Interestingly, I appear to rotate pencils to the right and pens to the left. That's even weirder.
Are you a rotator? Do you keep rolling in a particular direction or is it random? Does your brain distinguish between pencils and pens?