The title is a bit over dramatic but, per the title, if you could contribute with one piece of knowledge to a book that every single individual should learn from in order to kickstart a civilization, what would be yours?
My personal choice would be the process of soap making, from scratch.
Not sure about the Greeks or Mesopotamians, but the concept of not burning down libraries might’ve helped the Romans 😂
“Romans go home!”
“Romanes eunt domus? People called Romanes they go the house?”