Mines pretty mental and annoying.
best way to explain it would be: If i click my fingers with my left hand I then have to do it with my right hand. Then I have to do it with my right hand first then my left hand. But because I started with my left I then have to do it with my right first.
I went through a phase of doing that when I was younger: if I did something with my left hand, I had to do it with my right hand as well. It got pretty wearing.
I also can't leave digital volume readouts on odd numbers. That one seems really common.