For me personally I would go back to when i was maybe 9 (when i started piano lessons) and i'd start really trying to learn music instead of just memorizing what my teacher was doing. Id also get a jump on voicelessons before my voice got low. Besides that I'm totally content with the way things turned out.
ps. "THEY TOOK OUR JOBS!!!" (south park "gooback" episode, is by far the funniest episode yet!)