How much do you know about your father’s childhood? Probably not very much. The main way you know about it is from hearing about it from him. He himself will remember a relatively small proportion of his childhood. And basically nobody would actually bother to perform the experiment in yesterday’s post where one attempts to remember as much as possible of one’s past. This implies that he has only told you a part of what he can remember himself, and probably a fairly small part.
How much do you know about your grandfather’s childhood? Probably even less, although it may be about equal, or even a little bit more, if you know him personally. But if you add a few more generations to to this process, very quickly you will arrive at a point where you know basically nothing about your ancestors.
Perhaps you know a little about the general circumstances of your family two hundred years ago, or even three or four hundred years ago, based on historical records, rather than personal reporting, but it cannot be very much, and it would have been even less for those in the past, due to progress in the science of history.
Someone might say this situation where we know only a little, or nothing at all, about our ancestors several hundred years in the past is a recent phenomenon. In the past, they might say, people spent much more time talking to their children, and consequently passed down much more of their history.
One might ask how we could know that this is true, even if it is. But in any case, there is some room for variation but not much. People in the past may have passed down more of their history, but it would still be a small proportion of their lives due to the fact that a person only remembers a small proportion of his own life. Consequently the above process will always take place, even if it may take a little longer in some cases than in others. Perhaps some people in the past knew a good deal about their ancestors who lived several hundred years before them, unlike most of us. But they surely did not know much about their ancestors who lived several thousand years before them.
Thus, as Qoheleth says, “The people of long ago are not remembered, nor will there be any remembrance of people yet to come by those who come after them.”