It is surprising what you can teach yourself to do with your off hand. For example, when in college I had a job where I had to use a lefty's computer (the lefty is a friend of KC's). Some people who used it would move his mouse around and struggle with the buttons reversed. I decided right away to just use my left hand. It came in handy a few years ago when I got carpal tunnel syndrome in my right hand. I just switched my mouse around while my right hand was immobilized.
On a more humorous note, I have a coworker who is missing most of his left arm (congenital). He always blames his poor hand writing on him being "a natural lefty."

The dude can do just about anything with one hand. Very impressive.