Ignoring the ignorance behind this post, it's not so simple. Most provinces you've got to change birth certificate first which involves several forms and documents signed off by your doctor. These forms aren't something simple and quick like a doctor's note for being sick. After that you can switch it over. Also, as a result the next time passport is renewed it would have be changed over as well. Naturally of course such things can also cause issues if you go to certain countries. It is by no means something simple, fast, painless or without potential consequence. Then there's the other issue entirely of living in a society with such a license, especially for someone not attempting to transition in the slightest.