Name something strange you do on a regular basis
I have a fixation with even numbers. The volume on my TV, stereo, etc. always has to be on an even number.
Mine is similar to that, although it is has to be like 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 etc. When faced with having to do something with an odd number, I imagine the closest even number and round it down (for example, if faced with something like 8000, I imagine 8192 and round it down to 8000).