This makes me incredibly sad, as he is one of those people that has taught me over the years in all kinds of ways. One of the most recent, and really rather unrelated to his fields, is the Gell-Mann Amnesia effect: https://en.wikipedia.org/wiki/Gell-Mann_amnesia_effect

Which is amusing, but also profound. Fitting it is one of the last things he taught me (not directly, of course!).