Dear God, reading this topic makes me feel so damn old! I'm 25 and just finished my MASTERS DEGREE while most of you are still in high school. How time flies!
As for me, high school wasn't the worst thing in the world. A few things I would have done differently, but apart from that, good experiences all around.
As an introverted person, it was hard to create lasting friendships outside of high school - very walled-up kind of guy. Everyone enjoyed being around me and I wasn't bullied at all. Never hung out with a certain clique but got to know many people from different social circles and got along very well with them - from the arts people, to the science people, the jocks, the metalheads, etc). They all knew I wasn't there to pick fights so they appreciated my company. However, I did spent more time with the groups that had a higher concentration of intelligent, creative people who certainly knew how to keep things interesting (not to mention, most of the girls were smoking hot!).
I was a lone wolf kind of a guy, almost like a mercenary, but that didn't affect me negatively. I was a top-level student, the teachers loved me... Looking back on everything, I was certainly too uptight and definitely should have relaxed a little bit more, probably let a few people into my life. As a consequence, my first actual girlfriend didn't come until I was in university and I didn't lose my virginity until I was 22, but trust me, enjoying those things with someone mature and not afraid of being themselves makes the wait entirely worth it!
One thing I do REALLY miss about high school was the music program - bari saxes aren't cheap and losing access to my horn made me inconsolable for a good week! Playing in jazz bands and forming quartets with other sax players was a ton of fun (one quartet played video game music for a school variety show and we got the most applause out of all the acts!). Nothing more fun than someone not part of the quartet recognizing a piece of video game music when overhearing rehearsals - one guy just feel in love with Terra's theme from FFVI and Lufia 1's port city music! So much fun!
And getting the acting bug by being cast as Vince Fontaine after the original choice declined... so much fun! Never acted before in front of HUNDREDS of people, but as an introverted kid this was an absolute THRILL! Many others were intimidated by I soaked it all in. Such a fun character! If there was one week I'd love to relive again, it would be my high school's run of Grease. Can't think of another time in my life thus far that has come even remotely close to being as fun!