How about teaching statistics, econ, and accounting? It seems to be an ever-present subject, yet there weren’t a high school classes for them when I went, and only one college course was required.

Not only do I need to use these things at least once a month — I often need to re-learn what little I know, and learn more information to understand whatever it is I’m dealing with. All I do is code and do random office work, and get involved in politics, sometimes.