Yes, I am a lefty... but you know that means we use our right brains.
In otherwords, some people can read books and descriptions, not me I learn by doing or watching and learn that way quite quickly. It's really quite funny Dalum writes out these training drills and I am "like huh?" until we step up and do the drill for our class and then I'm in the "Oh! that's what you were talking about!"
As for which handed attack, that is not an issue for me. I live in a right handed world, and there for train to ambidextrous. The only thing I really fall short on is the range of motion my right wrist has vs my left... but my punches are just as strong.
Oh yeah and in class teaching drills I do naturally perform the drills with my left side first, and yes that does confuse the kiddies, I think it confuses Fred sometimes too.
I firmly believe that being a lefty is an asset, it's helped me out in-class sparing many times, as well as when I was in college doing SCA heavy weapons training. (most my opponents realized I was a lefty after they got hit)