So does sorting candy. Skittles, M&M's, Mentos, Runts.... All of which I divide by color.
I mean really this extends further. I mean think about it. I eat my lucky charms cereal first, marshmallow last. I sort my shower products. Conditioner and shampoo alternating pairs. conditioner 1, conditioner 2, shampoo 1, shampoo 2. laundry = blacks, jeans, blues/greens, white, reds/purples, browns/yellows..... I'm in OCD denial.
What are your little quirks?