This Christmas, my brother-in-law doctor was telling us stories about his patients and some of their strange behaviors. Then he moves on to his own daughter, saying that he always thought he would be the one to seed his children with OCD, but it's really his wife (my sister) who's the crazy one!
He revealed that my oldest sister counts things in sets of five. My youngest older sister counts in sets of 16 when she runs. I count whenever I do some repetitive action, or I'm waiting for something. I clap in sets of eight, I push the volume button on the remote in sets of four, and the volume in my car must be set to 12, 16, or 20. When I fill up my water bottle, I count to 16 or 32.
Of course, it's not really OCD because I don't feel compelled to do these things against my will, I just feel more comfortable doing them than not doing them. It's more like obsessive compulsive personality traits than a DSM diagnosed disorder. I don't talk about them much because people just look at me funny when I do. Which is why it was so strange to find out that two of my sisters do similar things with counting, and have special numbers too.