As for the issue at hand...how can a people build one of the greatest structures on this planet...and then lose the knowledge of how to build it...unless they never built them...but just fixed them - as Thunderbird alludes to! Human nature does not change - each is envious of the one that came before it...thus, every Pharoah would want a huge pyramid...why build a tiny pyramid...or no pyramid at all? Are we to believe that they had different values than us? I highly doubt it? Man cannot change much...as evolution is a very slow process...that point is made quite clear on this site...so then...Man will always be envious and vain..thus, the construction of pyramids would have continued if they were an aspect of the Pharoah and his afterlife journey! We still bury people if we are Catholics...and that has stayed with us well before Jesus appeared upon the scene...and I am told by Egyptologists that the Grat Pyramid is not that old...so we must assume that human virtues will have stayed the same - and each Pharoah would want to equal or surpass Kufu's great landmark!