I can barely remember my teen years, which I think is a subconscious effort on my part to purge them from my memory.
My health deteriorated when I started College, meaning I had to take a month out, which wasn't much fun. I was going for blood tests every week - although that DID help cure my phobia of needles; I have very thin veins, so it normally took seven or eight tries for them to get blood from me, meaning a lot of poking - and had therapy at my doctor's insistence as a compromise for not going to hospital (which is where he wanted to put me) so I wasn't in very high spirits. Then I fell in with a very dramatic group of people in my second year...several small hormone bombs exploded in my face that year; in many ways that was worse than my health problems, because I wasn't really equipped emotionally to deal with any of it.
Things started to take a turn for the better when I was 18 and went into University - I'd mellowed out a bit by then, and so had everyone around me; education became enjoyable, so life started to look a little less bleak - but before that I can't say I really enjoyed them. In hindsight, I'd love to trade the problems I had as a teenager for the problems I have now, but I suppose hindsight makes everything look much rosier than what it was at the time.