Things get much more interesting with more complex things like golf, snowboarding & skateboarding, shooting, etc. These things all have left-hand optimized equivalants (eg: left handed clubs, snowboards with the bindings set top "goofy", guns with the safety on the opposite side, etc). In all cases its a tradeoff -- you can learn and get good on the equipment designed just for you and then wind up sucking when you are handed equipment that is used by most everybody else or you can just learn to use the "normal" equipment even if slightly suboptimal. Guns, for example, eject their used shells off the right side of the weapon--good luck getting one that ejects off the left side so you can old it opposite of everybody and not have hot metal land on your face.
Computer mice are the same deal... some of those bastards are even molded explicitly for right hand use and are pretty uncomfortable in the left hand.
Being left handed gets weird quick because you are in a minority that most product designers simply don't consider.