My aunt lived to 94 and was in a retiremement community outside Boston. She never married (had some long term relationships) but was always interested in people. I used to visit regularly from the UK, and she was always introducing me to people around the community, nurses, helpers, gardeners, whatever. She would invariably give me a potted life history of these people, who she might only have known a few months.

No need for crosswords or other activities to keep her brain active - talking to people and remembering their stories is what kept her going!

Before moving to the community, she had a house in Cambridge (Boston) and let out the upper floor to students, post grads etc - and kept up with many of them long after they had left. Connection was definitly a skill of hers.