Dating all the way back to Neolithic times, the mortise and tenon is the oldest wood joint known to mankind. While the specific provenance of the joint is unknown, I’m willing to bet the inventor wasn’t a virgin. In the thousands of years since, craftspeople have developed an almost absurd variety of joints, some of which you learned in the ID shop at school, some of which you’ve never heard of, and that one that you can always see in your head but have forgotten the name of.