When I take showers, I cross my arms across my chest like you would when standing in an impatient way, let the water build up, and then release it and let it splash at my feet. Shower time is also my band practice. It gets pretty intense.
When I pee, I always try to hit the side of the toilet, so as to not make the loud splash noise of pee hitting the water. When I pee I also sometimes flush in the middle of it and try to beat my toilet in a race to the finish.
When I shit, I look at the toilet paper after wiping to see if I'm finished. I didn't think this was an anomaly, but I've met far too many people that say they don't do that. Those people are not welcome to sit in my chairs. I also take my pants off all of the way when I shit, only at home though. Sometimes if I'm taking a particularly long dump, I read the back of shampoo bottles and other various toiletry items, for no real reason.
When in a car (not driving) ever since I was little, I've imagined a little man running along side the car dodging shit and jumping over cars. I also used to think about, and still do, a game I used to play with myself. The car shot out lasers to kill the other cars. If the passing lane was on my side, it could hit the other cars. If the passing lane was on the other side, our car was vulnerable. Certain street signs gave different power ups and let my car and weapon do different shit.
At my computer and other places when possible, I often sit with one leg under the other until it starts to get sore or falls asleep. Then I switch legs.
Sometimes when I need to get up to get something but I'm feeling particularly lazy, I sit there and try to force-pull it to me, in hopes that one day it will actually work. I also occasionally try to fire lightning or some other magical energy from my hands, just in case I'm the chosen one.
Whenever I'm doing something, I often find myself asking this question in my head: "I wonder how many people in the world have done or thought this same thing?" I then question how many people have wished they could know that, too. I want to be able to pull up a statistic of anything in the world.
When I was a kid, things in my peripheral vision bugged me when I was trying to focus on something, TV especially. If something was lying around or out of place and I could see it, I had to move it to focus. This went away as I grew older.
These are things that I and a good amount of other people do (although you would be surprised at how many people find a lot of these things oddities). I just find a visual compilation amusing.