There’s a popular conspiracy theory which states that, tens of thousands of years ago, extraterrestrials came to planet Earth, mated with cave-women, and created the human race as we know it. It is believed by these people that they taught them many things (including fire, science, and building the pyramids) and were worshipped as gods by the humans.
Of course, I don’t believe it, and there’s pretty much nothing supporting these claims besides the arbitrary connection between certain ancient images/art and modern or futuristic technology, which I seriously think is a coincidence.
There was a time some years ago when I might actually have been interested in the concept. I wouldn’t say I actually believed in it, but it was interesting for a short time. But then the idea of aliens coming to earth to create mankind just seemed dull to me, mainly because the people who espoused these ideas were, whether knowingly or not, trying to derive the gods of their essential quality by making them gods into physical, tangible beings, when in fact they are spiritual, not physical.
The gods may spring from a spiritual realm, or from the mind, or from the spiritual realm within the mind, but they are certainly not physical beings. The whole ancient astronauts thing just takes spirituality and mysticism away by replacing the gods with aliens.
I also think that the people who believe in the ancient astronauts theory seem intent on denying evolution. I think they don’t like the thought that we evolved from apes, because they want to think we were created, with a purpose in mind. They still want to think of the human races as separate from the rest of nature.