Best Medium column ever, Paul! Nice to see you working in your element (pun intended, perhaps not achieved). I understood about 0.1% of it. But I did attend a Feynman class once. I was in dummy-track physics at Cal Tech, which did not teach from the Feynman lecture books, but they pitied us and had Richard come in to give one class for us as a treat. I've eaten lunch out on it ever since!