Re: How/why then did they fall?
extremely hierarchical, totalitarian gov's are inherently unstable. eventually someone of low ability or weak mind inherits power and everything goes to s---. rome conquered egypt precisel because at the time it was governed by a republic. many voices in a strong sytem is more efficient and more powerful than a totalitarian regime like in egypt. when rome went to the ceasers, that was the beginning of their downfall. eventually they too had completely insane people inherit power and it was a long slow slide from there.
the more democratic a gov is, the more stable it is, for many reasons. those in power need to be regularly replaced by others who are in touch with whats really going on, thats just one reason.
living in ancient egypt would have been great, IF you were in the upper 4 or 5% of the elite. but if not, you suffered and lived a life of pure drudgery, it weren't pretty. all of their wonderful technologies were strictly for the elite, not the average person (you know like you and me) if they had learned to share, perhaps they would have remained around a litte longer.