Procrastination and not completing things are probably the two main things for me (there are probably about 10 smaller things that could be considered bad habits).
I used to do that as well. I still play puzzles in my mind with tiles on floors or walls, as if they're a chess board or a course that I have to complete in some way.
I guess a weird thing that I still do (but people don't know I'm doing it) is when I'm in the passenger seat on a car/train and I'm looking out the window, I'll imagine a computer game character outside jumping over cars, swinging around lamp posts, and bouncing on peoples heads - used to do it loads when I was young, kinda just kept doing itmostly when I'm bored on a long trip.
I used to do that as well. I still play puzzles in my mind with tiles on floors or walls, as if they're a chess board or a course that I have to complete in some way.