In the last year I have noticed changes with my mother such as changing stories of our past, and recently telling stories that are mine, revising them as her own. I am familiar through Alzheimer's with my grandmother, who lived with us her whole life,so I am familiar with it. There is also much re-telling of the same stories all the time, but she knows she does it - even states "I know you've heard this before" but then launches into it.
She is still mentally with it; the history revision is most concerning. Also, she will interrupt me in the middle of what I am talking about to talk about something of interest. My husband asked her about this and she just said that when she thinks of something, she doesn't want to forget it.