What Have I Forgotten?

I'm teaching a graduate course in HCI, and I've learned one thing so far - how awfully much I've forgotten already. We're getting into patterns and pattern languages, and I'm alarmed to say that although I have a vague recollection of this subject, I haven't been able to use them in the field much, so they've receded into my mental archives. The same is true of other things. Names for rarely-used prototype techniques. Details about the types of conceptual models. The difference between categorization and classification. I know this kind of forgetting happens, but it's not supposed to happen to me.

Still, teaching these courses keeps the information fresher, and that's comforting to me. It's one reason why I keep teaching, even though sometimes the cognitive loading of work, home, and two or three simultaneous classes can get stressful.