The lectures themselves weren't that useful to me, although learning to interpret the pattern of confusion was invaluable (like looking at a code diff, where it doesn't tell you what the problem is, just what the difference is). Often, even the textbooks weren't (another exercise in pattern matching, and comparing with other sources). I spent a lot of time learning the material in my own way, then learning the mapping between my understanding and the way that it was being taught in class.

The topics in class acted as a decent map of the "tech tree" involved in the pile of topics to study, and a possibly-appropriate order to learn them in.

Everyone thinks differently. Do you have a more efficient idea an "expert" to convey a large number of concepts to a large group of people? What's your preferred method of learning?