I hated high school. I got a great education, but a lot of my fellow students were stuck-up, obnoxious, well... JAPs. Think "Heathers" or Cordelia from the first couple of seasons of "Buffy the Vampire Slayer". If you didn't have the latest shoes and handbag, if you or your parents didn't drive a Mercedes or BMW, you were out.
Plus, in high school you are still treated like a little kid, even if you're a senior. I'm sorry, an 18-year-old shouldn't need a hall pass to use the bathroom.
College is so much better. You are treated like an adult - I think that's the big thing. If you want to skip your 9am lecture to sleep in, nobody's going to call your parents or drag you to class - but it's on your head if you've skipped so many lectures that you can't pass your exams.
In the social scene, it doesn't matter as much how much money your daddy makes or what kind of car you drive; your social life is of your own making to a large degree. Yes, it can make a difference what fraternity or sorority you're in, if any, but driving a Mercedes isn't going to get you into a "top" house.
I wear my college class ring frequently. I don't even own a high school ring.