"I know you..."
The speaker was an elderly man who was with two middle-aged adults, presumably relatives. The man was addressing my elderly father as I was escorting him from the parking lot into a restaurant somewhere in southern Minnesota. The other man's companions looked startled. My father, as was his fashion, immediately began the "routine"- "who are you, where are you from, did you ever know so-and-so?" Much to everyone's surprise, the man did grow up in my father's hometown (several hundred miles away) and after a few more questions on both sides it was ascertained that the man had gone to school with my father's brother, and my father had known other of the man's relations, back in the thirties.
We all went into the restaurant, and as we waited for a table, one of the man's children mentioned that the man had a fairly advanced case of Alzhiemer's disease; he remembered little or nothing of his recent history. But he did know a face from the past, and he was grateful for the connection. My father (who is now deceased) would get a little confused about recent events in his later years, but never lost the memories of his past either. Perhaps the moral of this story is to live your youth to its fullest, so that its memories will be a comfort to you in your old age, however I doubt that there are many children who can grasp the concept.