Ok, Jack wrote something that needs to be said and understood about the Ancient Aliens movement. He raises a massive issue that really needs to be addressed, and not in the Ancient Astronaut crowd specifically, but in my sphere, your sphere, and every magician's sphere.
One of the arguments the Ancient Astronaut crowd often puts forward is that "If we could just barely do it today with all our advanced technology, how could those primitive tribes have possibly managed it?" In this argument, "primitive" doesn't just refer to the technology, the tools they have, but also to their minds, their intellectual capacity. Modern folk start with the assumption that because we know more about how the world works, our intellectual capacity is therefore much greater than those primitives.
It's not. The human brain hasn't changed much in the last 10,000 years. Advanced maths and sciences might not have existed back then, or they might have, but the brains we have today performing complex astronomical calculations are the same brains they had back then. The difference was the level of technology and the level of effort increase because they didn't have machines to do the work. They had slaves. They could look at the world and figure out how to drain a swamp and build a pyramid, as Jack points out.
Modern brains are not better adapted to processing higher maths than the brains of the people 10,000 years ago. The pyramids prove it. We tend to think you can't do advanced geometry without a scientific calculator, but we're wrong. They were doing complex equations with sticks and rope, and modern folk have the audacity to say they weren't smart enough to build the pyramids. Whatever, dumbass.
But the Ancient Astronaut core belief is that human beings have been visited by extra-terrestrial entities across time who brought advanced technological and other inspirational ideas. That fundamental belief is something I agree with entirely, I just don't think they were physical aliens in space ships. I think they were the same spirits that bring us things like Enochian systems of Magic.