Writing came to India rather late, compared to the fascinating developments of philosophy and higher thought. And ever after the introduction of writing, without the advent of printing,record keeping was not easy. Most of the ancient knowledge came downthrough oral traditions and rote memory. Indians produced people and methods with fantastic memories called Sutradhars, I believe. And they had tremendous twchniques (sutras) to aid the memories, like the Brahmasutras. Writing came to India rather late, compared to the fascinating developments of philosophy and higher thought. And ever after the introduction of writing, without the advent of printing,record keeping was not easy. Most of the ancient knowledge came downthrough oral traditions and rote memory. Indians produced people and methods with fantastic memories called Sutradhars, I believe. And they had tremendous twchniques (sutras) to aid the memories, like the Brahmasutras.