The only reason I can do adequately at all with my left hand is because I very nearly lost the tip of my right middle finger when I was eight. I was bandaged and/or having physio for months and had to keep doing normal things somehow. My dad taught me quite a few tricks as he was actually left handed but had to become right handed to join the civil service. I have dropped dramatically from the standard he got me too but then I've never had any reason to be left handed since.