A good recollection, Charles. I can recall visiting some science fairs in the late 1950's and early 1960"s and seeing various computational functions executed in hard-coded relay logic. And I have seen some of the older industrical control panels with a hundred or more of the little "ice cube" type relays, all running some fairly complex machines. Those were more the logic type of relays, while the cast-offs that I had were more toward the power types, with contacts designed to switch ten amp loads all day long.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.