One for me, no matter what it is, TV, phone, radio, anything with a numbered volume, it has to be on an even number. I dont know why. Just irks they hell out of me to see it on an odd number.
If im riding in the car and someone turns the radio up or down, I ask them to make sure its on an even number, if not i gotta make sure its even.
Come to think of it, on my gps, where it tells the speed i always gotta make sure its an even number as well.