Perhaps the larger message, Emily, is that your grand stayed active his entire life. That alone, along with good food, good friends and a purpose (like the farm) will ensure happy aging.
The day I turned sixty, I went scuba diving in the morning and horse riding in the afternoon in Costa Rica. Then I trained most of the year and climbed Kilimanjaro. After that I never looked back. My gift to myself at 60 was the life I always dreamed of, and am now living, as an international adventure traveler. At 67,the only thing that's grounding me is Covid. I'm already prepaid to return to Mongolia to ride the reindeer.