Periodically there are questions here about dealing with burnout and learning to cope with technological change/churn. Someone who's been doing it enthusiastically for over half a century sounds like exactly the kind of person who could offer advice on that. Do you have any?
The one thing that comes to mind is to avoid the "hammer looking for a nail" syndrome. I see this all the time, especially in academia. Rather than worry about learning all the latest stuff, concentrate on solving the problem at hand in the simplest and most effective manner. If that requires you to learn new things, then that's a great time to expand your repertoire - working on a specific problem. Of course you have to strike a balance, but mainly concentrate on solving problems rather than being up-to-date on all the latest stuff and trying to find the proverbial nail for your new hammer.
