The hole culture of those times is just, a little bit off. I mean we were thought a completely different things in the school books, then it is evident from the latest discoveries that it is not so.
These were not some limited, small minded 'starter' cultures with no knowledge about the world and technology.
The materials which they used, how they used them, techniques in the building ... nothing fits in.

At first we were thought that the slaves were the engine who dragged up the whole construction, but in the latest thing out, it turns out that only the masons were included in the construction, slaves were actually a working flock in the production of the food and similar, unrelated simple jobs.

Where and how the pyramids were constructed is just mind blowing.