I'd figure there were a half dozen or so starting points for trying to understand ancient history, or at least as much of it as we have. You might have noticed the funny thing about our supposedly being around in one form or another for a million years or more and for some inexplicable reason only having 3000 or 4000 years worth of history...
I mean that would at least do for starters.
“The Origins of Consiousness in the Bicameral Mind”...one of the deepest books I’ve ever read. Sagan’s “The Dragons of Eden” is right there also.