In all seriousness, whether its aliens or not, I really don't think so. But, I do think there is a case for there being some advanced society that existed that travelled the world and was lost to history somehow. Having pyramids on every continent for example, that are all eerily similar in style. How did so many different cultures come up with same exact design?
Our brains are structured and fuction the same, regardless of our "culture." This means there are ways in which everyone, regardless of where they were born, or where they live, will deal with similar stimuli similarly. Consider, beliefs are fashioned to be psychologically
pleasing, to diffuse or to eliminate psychological dilemmas. Since we are all human, since our psychology is then eminently similar, shouldn't the expression of said psychology be also similar?
To get deeper, our "differences" are more pronounced in our "conscious" minds, since this is where we posit ourselves as "individuals" and so
separate from each other, so the more we think of ourselves as
selves, the less likely it seems to us that we should have things in common. Of course, our conscious mind is just the tip of the ice berg. Our unconscious mind is the real driver, as research has continued to show. Bakker speaks about this often and "the darkness the comes before" is
exactly a reference to this.
To bring this back around, religious beliefs and especially the symbols that go with them, i.e. pyramids, mandalas, trinities, what would become "alchemical" symbols like trees, lakes, gold, more ancient symbols like the Great Mother, or the Old Wise Man, or literal "events" like a Great Flood, permeate all of our unconscious minds. Simply because these are not individual symbols in the sense that they are tied to a
certain person, or culture, time, or place, they are tied to the fundamental way in which our brain is structured, the way our brains function, and specially, how our brains makes sense of itself and the world.
So, to sort of give a TL;DR, I don't see why there needs to be some "lost advanced culture" traveling the ancient world to spread these ideas. They were, in fact,
still are, present in the very
fabrics of our minds. We as humans all started in the same place,
we traveled the world,
we brought (realistically speaking) the same
brains everywhere and so the same problem solving methods, the same thought processes, to deal with the stimuli of the world. Consider, our brain is our measuring stick for the world. We brought that same measuring stick with us everywhere we went. Is it a surprise then that things turned out the same size over and over again?
There is a lot of interesting ideas put forth that doesn't have to explained by ancient aliens. I mean look at the history that you was taught as a kid. Every decade, evidence is found that pushes the timeline back farther and farther, on how humans advanced as a species. Its all very interesting to me. Now granted, some episodes and the theories they put forth are absolutely bat shit insane, I agree. I just believe that the history we were taught about how humans advanced is not the way it truly happened.
Well, here I agree. We fancy ourselves much smarter than those who came before us. The truth is, they were probably smarter then us, in general though. Consider, we looked at Egyptian hieroglyphs for years and years and contunually misinterpreted them, seeing what we figured we
should see.
Consider this case. We saw that painting and of course figured, "look at those silly primitives, pouring water on the ground to consecrate it before they moved their sacred statue on it" because that fits our narrative of unsophisticated, superstitious primitives.
The real fact of it is they were actually
very clever. They didn't need all sorts of high tech nonsense to achieve great things. They didn't need aliens, or some high tech culture to teach them how to solve problems, for the same reason why a basketball player doesn't need a physicist to teach him about vectors, arcs, air resistance, centrifugal versus centripetal forces and a whole host of other very important things, just to toss a basketball into a hoop.
We've got tons to learn from ancient peoples, because they lived and thought, far more in concert with the world around them. This post is probably long enough as it is though.