I've always been a "counter". Almost Every time I look at a guitar I count the tuners, even my own and the 12 string especially. I always count the spokes in wheel covers and the holes in between.
I try to count the windows in the Law & Order set but never get them all.
I think it's more boredom than anything, and I can stop in mid count and say, why am I wasting my time doing this?