I'd guess 90% of the chemistry I once knew was learned on my own, independent of college. What I think I did learn in grad school was how to approach problems, and enough background to learn what else I needed to learn. College at best provides a framework, a mostly empty canvass, with lines already present one can fill in later.
I changed from being an organic chemist to a polymer chemist at work, which is not that unusual, but it was some work, and I never knew for sure if I had it right initially. We hired a "real" polymer chemist and he said we had it right. And did more good work.
We had long discussions about the topic later, very useful.
I think college provides a license to learn as much as learning.
