@sozobe,
My first five years were in the early sixties, five years because I kept changing majors (ending up with bacteriology). I learned how to learn in a concentrated way on many subjects while I now forget much of the detail. I learned how to use the library of those times, how to write papers in the middle of the night, how I could be fascinated about things I started out with no interest in, and best of all, how to question assertions - something I didn't learn much about in my parochial high school. I guess I think of those years as my "waking up".
One singular sentence comes to mind as a brain spit: Ontogeny does not recapitulate phylogeny.
A decade later I took dozens of studio art courses. I remember most of those, and best remember that I learned how to play with paints (or anything else).
A decade after that I studied landscape architecture for four years. I've retained most of that, most strongly re matters of design, but also a fair amount of the technical side of it. I nearly died at the time from a site engineering type class like grading and drainage but later found working that out re real properties to be great fun - and still remember all that. Oh, re changing - my eyes opened wider, much wider, to the city and countryside around me, every day, all day.