Earlier quoted context omitted.
Most left handed people I know (me included), use the mouse with the right hand. Might be a bubble though, but I never thought to get a left handed mouse, or left handed scissors or most left handed things. There's a few things that really don't work (I play my drumkit with hands reversed), but most things are fine.
A lot of left-handed people are actually cross-dominant or selectively ambidextrous.
It's specific to each task but I can normally get the left handed version as good or better than the right. I am willing to bet most people could do this, you just have to spend a bit of time awkwardly re-learning.