I went to a very small rural school, so the pot of people I could know was tiny, really.
I was fine. I was a little young for my years socially, but not at all academically. People really disliked that I could get good marks. So I got accused of thinking I was better than everyone else, and that has made me very careful not to ever do that. (I actually think that's turned out a positive effect on me, even though it was difficult at the time, obviously. I'm in my 50s so have had a long time to mull it over.)
I had friends, but for a couple of years in the middle I had very few friends because someone I thought was a friend spread a lie about me and it kind of stuck. I find I'm angrier about that now than I was at the time. I kind of went into this very practical state of thinking, ok well I will simply do x,y,z and not interact or react. As these things do, it fizzled out, and we became friends again, and the worst people left school early anyway, but wow what a headfuck for a couple of years.
However in that time I read a lot, I listened to a lot of music, I wrote, I was pretty creative actually! Fuck that person, she never had anything like the positive effect on me that those couple of years did.
Then my last two years were great, I went out a lot and had a lot of friends. But 'a lot' doesn't mean a lot in a rural setting, where everyone knows everyone. I'm only really Facebook friends now with them but I think back fondly.
Then I went to university and left my family (a positive for me) and that's when life really started. Not that it's been easy, I am definitely prone to monitoring if people like me or not, over thinking a lot about interactions, and all that is probably because of school. But on the other hand when I meet people with whom I hit it off, it goes well and I have friendships that are decades long, just not with people from school.