I got a degree in EE, but spent a year in CS (don't ask). Some years back I totted up what have used since graduation that I actually learned in class. I didn't get a CS degree because it is too easy -- you just read the book. So I didn't learn any CS there, I had already read the book.

The only thing I have used since graduation, for work, that I actually studied for a class was big-O notation and reasoning.

But! Every week, in every engineering class, they assigned problem sets. Every week I read them through and knew, with certainty, there was no way I could do them. Then, every week I turned them in, completed correctly.

So that was what I really learned in school: that I have no real sense of what I can learn to do, and do. Since then, I have just done things, without worrying about whether I was really capable.