I started going to see independent/"underground" music at a very early age - I somehow convinced my parents to drive me to CMU in 1993 to see a couple of shows; even though i had to leave before the final acts, I'm pretty sure I saw Guided by Voices on the Vampire on Titus tour, though I don't remember anything of it.
Most of my high school years I dreamed of being able to go to things like this regularly. There was an odd smattering of live shows I was able to attend when I was 14-15 years old, but just a few, which I have no posters saved from. (Number One Cup and Shale at Luciano's was a big one; also I saw J Church there one summer).
By my senior year, I was just waiting to get high school over with. I started to attend gigs more regularly, and even started playing in a band called The Blazing Bulkheads with Weird Paul. This Melt-Banana concert was something I look back on as a major turning point - the transition from high schooler looking in, to person actually being part of the music scene.
I'm not sure actually why I regard this so fondly. I didn't stay to see Melt-Banana and I didn't like the Monorchid at all. But I saw The 1985 for the first time, who I only knew of as being a new band by Jeff who used to be in Vehicle Flips, a local pop-based band whom I loved (and still do). The 1985 blew my mind. I didn't recognise their influences at the time (Nation of Ulysses, Six Finger Sattellite) so to me, this was a radical approach to rock music. I was instantly a massive fan. I went to every one of their shows that I possibly could, probably seeing them 20+ times. I bought their t-shirt that night, with semi-functional glow-in-the-dark ink, which I still have (though it's pretty ratty now).
And to make it better, their drummer approached me after they played because he recognised me from Weird Paul's band the previous month. I met a bunch of people that night - I think that was the first time I met Luke who I later played with as Land. And, I saw Arab on Radar for the first of maybe ten times, who dismantled rock music even further - this was their earliest lineup, with the heavy farting bass sound and the most wild, aggressive stage show I had ever seen (or at least tied with Xerobot, who I had seen at Luciano's the previous summer).
Todd from Shale gave me a copy of their Truth/Lie 12' after the show (for free! just because he was nice and I had met him before through a friend) and I went home feeling like a whole new world was opening up. As soon as I finished high school.