Very common story. You play when you're in single digits, early double digits. You reach teenagerism, and your angst tells you "Well I'm too cool for this", and you're gone for years. Then one day when you're older, boredom trickles in and somehow you find yourself back on Neopets for one reason or another. And you find it fun. You don't know why, but you do.
That's what happened with me, anyway.
I quit actually not because of teen angst, but because I found myself so addicted that I needed to quit. I was legit addicted and couldn't stop playing, haha... well, eventually then I found neopets to be a bit childish. But who cares, it's fun and it's less addicting than playing WoW, so why not?