I'm right-handed but trained myself to use my computer mouse left-handed due to elbow pain. It is so awesome to jot notes w my right hand while mousing with my left.
It took me a long long time to get comfortable mousing with my left hand. I usually dock my laptop so that I have a full-sized mouse & KB. But when I use the laptop by itself, I forget how to right-click because of the ambidexterity of it all.
Even though I'm a lefty, I've always moused with my right hand. Mainly because in school, I often wasn't able to move the mouse to the left hand, because they locked the cable to the PC and to the desk in a way that only left you so much cable length, so you couldn't physically move it any more then was required to use it.
Stupid assholes stealing mouses, always gotta ruin it for us lefties.