I think that might be underselling the intelligence of early societies, though. People weren't stupid, they just didn't have the specialized institutions of education we have today. Societal structures took time to develop and iterate.

If you abandon modernity and return to a hunter-gatherer way of life with small communities, you will end up losing most of that knowledge after a generation or two if there are no institutions to continue providing education. But having those institutions wouldn't fit a hunter-gatherer way of life.