I had a couple of sips of...I think it was rum and coke, or Barcadi and coke, when I was around six or seven. Didn't turn me into an alcoholic...in fact it ruined a good coke in my opinion at the time.
Had a bad experience with mixing my drinks at a house-warming party a few years ago, felt rather terrible, vowed not to feel that terrible again and rarely touch the stuff these days.