alt Hacker NewsMan, that makes me happy. I'm guessing your grandmother was a very upbeat, happy person who dealt with change well. My mother's the opposite, so now every little thing going wrong is the end of the world. It's rough, but I also get to see these moments where I can see how she was when I was little/before I was born, and those are moments that I do really enjoy.
These stories scare me. I'm happy that you were able to enjoy glimpses of your mother's past.
Mine is showing signs that several of us believe to be dementia, but she refuses to be seen and screened. It has gotten worse over time - repeated conversations, sometimes inside the same phone call, and a shift from "can't remember things if she doesn't write them down" to "needs to ask on multiple occasions because she hasn't remembered to write it down" - but not to the point where she seems to be a danger to herself.
I love my mother, but she is difficult. She also has grown with age. While she is difficult now, she used to be abusive and manipulative. My father would never speak ill of her, but from some things she's said I believe she was worse before she was raising us. If my mother regresses to an earlier state of mind, we will both need professional help. She will need professional care, and I will need help to not internalize the way she treats me.