> Based on the folk & religious beliefs of a great many cultures, it's easy to argue that human societies have a very strong bias toward believing in anthropomorphic supernatural beings - be they angels, demons, ghosts, spirits, or whatever. Are von Däniken's ancient aliens anything more than "random" meme, which turned out to be an excellent fit for the social environment it found itself in?

The supernatural beings are a way of explaining a world that is not completely understood. Even today we don't completely understand it but we have dismissed the idea that something intelligent is behind the inner workings of the world around us.

Now if you have supernatural beings it is not quite a big leap from going from supernatural to just technical advanced. Any sufficiently advanced technology is indistinguishable from magic. For us modern readers this removes the supernatural part while it keeps them for our ancestors.

I wouldn't call it a random meme. But it was an excellent fit at a time where we started to explore space and could even imagine becoming ancient aliens to other civilizations in the future.