"4 habits to help you stay mentally sharp in retirement by Jenna Schnuer suggests:

• "Stay–or get–connected" — beware social isolation, maintain and develop friendships, take classes, do volunteer work, etc
• "Don't stop moving" — exercise, whatever types work for you, at least half an hour most days
• "Send stress packing" — sex is excellent (the author lists it first!) to promote better brain chemistry; also valuable for destressing are sleeping neither too much nor too little, practicing yoga, and maintaining a budget to minimize money worries
• "Find a new way to work" — seek meaningful employment, perhaps unpaid or part-time, or in a new field, or at a new place

... all in strong resonance with key points from a 2010 pre-retirement class, captured in Retirement Tips - 1, -2, -3, -4, and -5. And don't forget the prime goal to aim for, when looking back at Life:

_{^z - 2023-05-25}