As promised...
I went to a really big state school for undergraduate. They had a strong biochemistry program and tons of research opportunities - exactly what I wanted. It was an urban campus in a city about an hour away from my family. I lived in the dorms for 3 years and then rented a room off-campus for my senior year. I had a fantastic college experience. I found my "niche" - people that became my family away from family. I was independent but was close enough to my parents that I could easily go home for a weekend.
For grad school, I moved to a different state and ended up in a very small graduate program at a medium-size university. It was in a large city with lots of exciting things that I wanted to do (museums! symphony! musicals! blues and jazz clubs!). Grad school was pretty intense, so there wasn't as much time to explore and meet people as in college.
What I came away with, that for me, going to a big school with lots things to choose from and a large enough student population where I could find people I had similar interests with, was a good choice. Really small schools might not have worked as well - if I didn't fit in, it would be hard to make friends. There probably wouldn't be as many research labs to choose from.
If I went back to school now (or after retirement)... I don't know, maybe I would study something like folklore? (And travel around the world to collect stories - that would be amazing) Or creative writing? Or maybe I would explore a different branch of science. Or maybe I would try coding. I probably would not go into history or economics.
What are some of the things you wish you had a chance to learn about?