Not remembering a previous conversation

(Chapter 12 Navigating Relationships While Living with a Memory Impairment in my book)

My mom and I were talking on the phone about something that we had previously discussed. I told her that unfortunately I couldn't remember the previous conversation. She gave me some of the details and it sounded a little familiar to me. I told her that I was remembering some of it but I just had no idea when this conversation took place. I don't even know if she explained when we had talked about this previously. I know that this has also happened with my daughter.