Pretty much same as me. When trying new sports or activities, bowling, golf, whatever, I spend a lot of time trying to work out which works best for me.

When I was in my early 20's with a terrible data input job I would use the mouse in my left hand so my right hand was mostly for the num pad on the keyboard. Efficient. But when I played pc games in the evenings I used my right hand - don't know why, just seemed to work. These days I use only.my right hand on the mouse but can happily switch if I have muscle strain or whatever.