The world is not set up for lefties. I have used my left hand for mousing, typing, trying to use scissors (not gonna happen), and everything else. I now understand my left-handed friends and their gripes about not having left-handed scissors. Trying to start the car has been an adventure, as has been shifting the car from park. I have to contort myself to buckle my seat belt. All in all, it's been an unpleasant experience for me. Now before my left-handed friends take offense, I am not slamming lefties. I am a right-handed person, so using my left hand for everything has been trying at best.
I guess I should add that with the tendinitis, I have been effectively one-handed in addition to be left-handed for the past month. That has given me a whole new respect for those who have only one hand and the things they are able to do with that one hand. I suppose if it became a permanent issue for me, I would learn to do more with just the one hand, but my problem is temporary, so it has been frustrating for me. I don't do dependence very well, and I have been fairly dependent the past few weeks.
I won't take being a righty, or having two good hands, for granted now. At least, I'll try very hard to not take it for granted.