I gave this a GQ because I was thinking the same thing and was going to ask something similar a few months ago.
I know two people that do this a lot. One, when she is going through problems, will talk to a handful of people almost every day, almost like therapy. She will call and talk about updates (she’s going through divorce) and then she will rehash the past. When she talks about other people, she’ll rehash stories from the past, or gossip about the people. She’s about 70 so I don’t think of it as a dementia situation, I think of it as she’s needy. I listen and a lot of it is interesting. While she’s talking, I can do other things in the house and listen intently. She tends to be funny so it’s enjoyable, although can be time consuming.
Another person I know that does this is an elderly lady where I live. Almost every time I see her, she will tell me about how her husband’s family has been here for the past two hundred years, and how her grandson is the fifth generation going to the public school. She will tell me about how when one of her kids was in the elementary school and the school was trying to teach the kids their address and phone number, her kid didn’t know and the school administrator told her it was a problem. She very proudly told me how she told the school admin that the kid didn’t need to know that info because the neighbor worked in the school, the kid knew the firemen, the kid had all these close connections, yada yada yada. She seems so proud when she talks about this so I act like I never heard it and it’s fascinating to me. She’s in her late 70s. I’m not sure if she is just proud of the stories and forgets she told them, or if it’s a bit of dementia.