Wow, it's been so long, I haven't thought about this in years, until I saw this thread..and brought back some old memories..
Same here, I started off as a predominate lefty, and do remember having a hard time learning how to write well with my right hand at 1st, I was told it was for my own good, why that mattered to anyone, I have no friggin idea, and it never made any sense to me, because my penmanship was better in my left than right, so I was ambidextrous for a while but I gradually stopped using my left hand more as time passed, and now have been right handed for so long, I can't write lefty anymore to save my life.. it now looks more like doctors scribble/scratch for a script. LOL
But I do notice myself reverting back to lefty in other things every now & then..so I think some things just weren't meant to be changed.