In Retirement, Feed the squirrels!
My great-aunt worked part-time well into her 90's. She lived until 105. My grandmother worked part-time into her 80's, and lived until 95.
What did I learn from both of them? If you have something to do everyday, it gives you a sense of purpose and keeps you going.
I worked in a large city, and I used to see an elderly man walking around and throwing peanuts out for the squirrels. I would see him everyday over a 28 year period, and as he got older, he continued to do this even when he needed to use a walker. It was an activity that he enjoyed, he got to do it everyday. It gave him a sense of purpose and kept him physically active. I retired and relocated. But, I'm sure he's still out there today, feeding the squirrels.
Find one thing that you love, and do it every day.