[samuell]

This. I tend to think a key to really understanding something, is the ability to put that "something" in to contexts at a wide variety of abstraction levels.

That's what I hated the most with uni: Some professors could write 10 blackboards full of formulae, but could hardly put together a few words to explain what we were actually doing. Unsurprisingly, I don't remember much from these lectures. Fortunately that is not all professors, but it worries me how large a percent of them were like this.