I have vivid memories or moments when I have been reminiscing some other, older happenings. Isn't it enough to just remember those memories? What's the point of remembering also when you have remembered them.
Sometimes the memory of those occasions can be more clear then the actual memory. Or at least when I try to remember it directly. Maybe I don't even remember the original memory anymore.
Thus could be just a way for the brain to optimize the memory. Copy over those old memories inside the new one so the old version can be let go. Maybe the new memory is stronger and so creates s stronger connection to the old memory.
I don't thing I have any deeper level chains of these. It's always directly related to the situation. I don't remember having those same things about themselves. Maybe they become unnecessary once the memory has been replicated within the new one. Or maybe when such things do occur they just update the pointer directly to the original memory instead of adding an extra layer there in between.