Earliest example of me pirating was when my dad used Limewire. I'd like to think I used it as well, but I doubt it since I wouldn't have known anything to look up.
Otherwise, in highschool I would go to different sites to find cartoons/anime that weren't available on Netflix (or Hulu back when it was just about the only competitor). This was before I knew what sites were safe, so I probably ended up getting viruses without knowing.