He invented a whole new symbolism and methodology for modeling constraints in relational database relationships (I should know, I was his copy editor for his Ph.D. thesis). Seeing him like this is both disheartening and frightening.
Eliminating all simple sugars can also be helpful, and increasing fiber sources, too.
I find that I have to train for older age: physical, mental, spirtual too, probably. Working at keeping some high-tech things familiar.
Some of that high-tech work is tough, because of un-expected, furniture movements and security changes in the MacOS - so some sub-routines no longer work (and I did not include notes for every occasion, re “What this sub-routine does” - duh). So, I have had to dig deep.
I keep an Algebra book in the car, so I can study while getting the oil changed. IOW, I (try to) develop tools for my older age.