I studied undergraduate mathematics, and I think it's a field which requires the student to spend as much of their own time as needed to understand a concept. Perhaps this could be said of all fields, but there is just limited time in a class to absorb, e.g. Euler's Formula, because there are several concepts in play, and if the student doesn't have a firm grasp or recollection of one of them, then they get lost at one step on the chalk board, and the rest of the derivation is useless to them. This happened to me many times, and I'd just have to make a note to go figure something out, and the rest of the class was basically useless to me. Once it became more acceptable to have a laptop in class, I could just just look it up right then, and not have to wait till later, but I still just tuned out the professor.
Perhaps this could be said of all fields, but there is just limited time in a class to absorb
Which brings us to that what can you expect to actually learn in a class anyway?
I'd say that for any non-trivial curriculum (which ought to include most of a university...) you need to read about the subject yourself and do your own learning. And once you do that where do you need the classroom? For asking questions, maybe? But a classroom probably isn't the most effective way to ask questions.
