The latter. My understanding of graph and complexity theory was a little weak, but about on par with what the average CS student actually remembers upon graduat

The latter. My understanding of graph and complexity theory was a little weak, but about on par with what the average CS student actually remembers upon graduation. It's not that difficult if you actually care about it. The great tragedy is that most people who study things don't care about them. I see this all the time: in any given subject, the people who think it's interesting are the people who will learn an order of magnitude faster, and actually remember it afterward. The ones who go in with the attitude of just grinding through won't learn nearly as much. This is why I think that the best way to learn any technical subject is to start on a project you think is cool, and learn whatever becomes relevant, with enthusiasm. If you start programming, sooner or later you'll come across this "quicksort" thing and hear that it's usually "O(n lg n)", whatever that means, and the next thing you know you're reading through an algorithms textbook of your own volition. It's freaky, but it works.