[Nervous Tick]

>> How about just keep working doing difficult and challenging brain work?

^^^^^^^^^^^^^^^^ THIS ^^^^^^^^^^^^^^^^^

“lifelong learning”

[Seaplaner]

Lifelong learning? Yup. I stay sharp by flexing my memory "muscles" all the time. If you can't name all nine SCOTUS members, all seven dwarfs, and all nine essential amino acids, that's a place to begin.

Learn (or review) calculus, that's a good one. Crosswords? They're available online, tons of them

Diet and nutrition? That's a biggie. Stay away from seed oils (omega-6s such as linoleic acid), excessive carbohydrates, and long lists of "ingredients".

Fish oil capsules, supplements with polyphenols, and vitamins...all good.

Exercise? you betcha. I'll be running in a 5K in a few weeks, in fact.

Birthdays? My 78th is rapidly approaching. Keeping my memory fairly sharp takes work, but it beats the alternative.