Using high school as a marker for what to expect for the rest of life is such a terrible idea. Just throw that in the rubbish and go experience people for yourself. Wade through the assholes and you’ll find tons of nice folks just trying to live.
It's true. I think the amount of attention highschool gets, from people saying it was the best years of their lives, to adults coming down hard on you to do the best thing for your future, to your peers seemingly having an amazing time while you're not, winds up making teens feel like it is indicative of how life will be in general.
It never made sense to me, but I wasn't having a GREAT time until I was in my mid 30s. I had something like a 7 year party. Disposable income, before the worst of my aches set in, and just doing whatever I wanted as long as I made it in to work.