There is an argument that essential knowledge was transmitted through myth. I am thinking specifically of Hamlets Mill: An Essay Investigating the Origins of Human Knowledge and Its Transmission Through Myth by Giorgio de Santillana and Hertha von Dechend
"Von Dechend has argued that the astronomy of the most ancient civilizations is far more complicated than we have hitherto realized. She sees myth as the technical language of a scientific and priestly elite; when, therefore, a myth seems to be most concrete, even gross, it is often using figurative language to describe astronomical happenings . . . Von Dechend's thesis that there is an astronomical dimension to myth that is not understood by the conventional archaeologists of myth is, I believe, quite correct" (Thompson
Other scholars have since concurred with the basic premise of Hamlet's Mill, that mythology and astronomy go hand in hand. Joseph Campbell even goes so far as to point out that the numbers associated with the ending of world, as recorded in the Icelandic Eddas, are identical to the numbers used in Hindu World Age calculations, and both ultimately refer to precession.
This heresy, when published, stirred up a hornets nest but the numbers in these myths combine rather frequently to construct meaningful precession numbers.
If these numbers are to be believed they need to be transmitted accurately down the generations. Poetic license due to the folk process would cause havoc -so where does that leave us?