Hobbies or clubs or whatever it is, apparently staying face-to-face social later in life massively reduces your chance of getting cognitive degeneration/dementia/Alzheimer's, or at least delays it.
My family saw this first-hand with my grandmother. My grandparents lived in Niagara-on-the-Lake for many years (before it was cool, yo) as my grandfather was in the army during the second world war, and then fire department, so was able to retire super early. My grandmother had a very active social life there, playing badminton with 'the girls', getting out and about in the town etc.
As they aged, my grandfather decided that they would get ahead of the game and moved them to an apartment in nearby Virgil. They would have been in their early eighties at the time. It was catastrophic for my grandmother, though. She didn't drive, and so was suddenly socially very isolated. The apartment they lived in was really build by and for the local Mennonite community, and she didn't connect with any of them, and Virgil is much more spread out than NOTL, so she was very limited in how much she could get out and do on her own.
Within a year or so, she started forgetting things, and other signs started popping up (leaving the oven on, forgetting names, etc.) That started a downward slide that saw her permanently hospitalised within a couple more years, where she stayed for almost 7 years with a healthy body and a failed mind. She outlived my grandfather, who developed lung cancer but was able to live at home right up until a few days before he died in palliative care. I know which one I'd prefer...
On the other hand, my great-grandmother and great aunt lived to 99 and 98 respectively, and had good quality of life until the end. They both had a relentless quality, where they simply didn't let setbacks slow them down. My great aunt fell and broke her hip in her early 90s, something that is usually fatal (and is what killed my other grandfather.) She refused to let it get her down, and was out with her walker as soon as she was home, determined to make it back to the mall she went to daily. It took a couple months to build up the strength to get there, but she did it. A small thing, but that refusal to give in made a huge difference. They were both extremely social, too, one in the apartment she lived in and the other in her retirement home...