I've been semi-active in the fandom since 2007 or so, but I've known about it since 2002. I used to draw and RP as an animal all of the time, but I never considered myself an actual "furry" until quite recently.
I discovered the fandom through a combination of roleplayers on neopets (back when it wasn't craptastic) who introduced me to anthropomorphism, and stumbling across furry art on Deviantart. Then I discovered Goldenwolfen, and I was absolutely enthralled with her work. I started visiting furry chat rooms on dAmn, made tons of furry friends, and realized that I was really drawn to this.
Eventually I just got sucked in completely. :F