I carry a light when I dive. More than one, actually; it’s dark inside wrecks. The primary light, though, is a big honking eight C cell (rechargeable, naturally) thing with a pistol grip. When it isn’t clipped off on my harness, it is in my hand. My right hand. Always my right hand. No matter how hard I try, how many times I switch it to my left for variety’s sake, the moment I stop actively willing it stay in my left hand, it jumps, unbidden, to my right.
Some activities require the dominant hand: writing, three point shots, cutting a steak are good examples. Try any of these with your off hand and you will make such a hash of things they’re not worth doing. Other activities you can practice with your left hand and become proficient---frisbee, shooting guns, dicing food, pleasuring yourself, etc. But the vast majority of us don’t practice such things with our off hand. It’s easier to do it with the dominant hand, so we do.
That’s how things happen with my light. It stays clipped on my right side, and when I want it I reach for it with my right hand, where it stays until I clip it off again. Sometimes I switch over and actually concentrate on keeping it in the left. Then I start thinking about something else, or move to manipulate or steady myself on something, or illuminate something in a crack or crevice. The next time I think about it or start paying attention again, there it is in my right hand. It’s not like the light is brighter or more effective when held in the right. What’s the deal?
So, a little social experiment for you. Something you use every day, as important to you as my light is to me. How about your PDA/cell phone? Try using that thing exclusively with your off hand all day tomorrow, and see how long it takes for your dominant hand to take over. Strange, huh?