I think the most obvious explanation, one that doesn't even require much imagination because it just coincides with the very concept of history and pre-history, is that people lost a lot of stuff when only oral tradition was kept and the threshold of complexity that could be reproduced reliably over generations was rather small and also asymmetric: stuff that could be kept inside of tales of general interest could be carried much further in space and time than things that would be specific or narrow in audience.
Even with written records and history, there were a few events of major destruction of records, as they carried a legacy of power structures, just as they do know.
Within living memory we had to go to privileged structures like the University to feasibly attain specialised knowledge beyond amateurish levels, across the disciplines. Just a little further back, reading and having many sources of information was for the rich in most of the world.
The beauty of it is that most of the trail of the current flow of knowledge and technological advance is very well documented, it happened very recently. What's more, it's well documented how it didn't happen previously for a much, much longer period. Before global trade, people had very little spare time to think of anything outside of their day-to-day, and at most of their local governance and the preservation of their livelihood.
Recorded knowledge, free(r) global(er) trade, communications super-charging each other and undergoing major breakthroughs during the Bronze Age and then the printing press and the industrial revolution, and then the hyperconnected world shortly after.
Can you imagine just how little would subsist if humans couldn't record stuff and communicate beyond locally for just a few generations, and we were too busy just surviving short-ish lives by foraging and hunting?
Even with written records and history, there were a few events of major destruction of records, as they carried a legacy of power structures, just as they do know.
Within living memory we had to go to privileged structures like the University to feasibly attain specialised knowledge beyond amateurish levels, across the disciplines. Just a little further back, reading and having many sources of information was for the rich in most of the world.
The beauty of it is that most of the trail of the current flow of knowledge and technological advance is very well documented, it happened very recently. What's more, it's well documented how it didn't happen previously for a much, much longer period. Before global trade, people had very little spare time to think of anything outside of their day-to-day, and at most of their local governance and the preservation of their livelihood.
Recorded knowledge, free(r) global(er) trade, communications super-charging each other and undergoing major breakthroughs during the Bronze Age and then the printing press and the industrial revolution, and then the hyperconnected world shortly after.
Can you imagine just how little would subsist if humans couldn't record stuff and communicate beyond locally for just a few generations, and we were too busy just surviving short-ish lives by foraging and hunting?