I have a family cemetery on my own 30 acre cattle farm. It's an acre and because it's designated as a cemetery, there are no property taxes on it.
There are about 25 people (or their ashes) buried there and I only know four names. My wife knows 3/4's of them but not all of them.
Unless the people buried are of some infamy or their family and/or friends remember them, it is not hard to see how people are forgotten over time.
Both my parents died a couple of decades ago. After my wife and I are gone, we only have one daughter who ever knew them when she was young. There is not gravesite for either of them. They were both cremated and their ashes spread to the winds.
So it won't take but two generations for my folks to cease being a memory in my family.
Yeah.. it’s a sad fact of our existence.