I see some people didn't get the obvious joke.. the big joke though is that some people actually think like that. As a little boy I was into Erich von Däniken and his books about how, basically, aliens made a lot of the "impossible to make for humans at the time" artifacts. But then my, at the time, 9-year old found the part where he wrote (paraphrased) "[photo of a sculpture made to look like a skeleton] This sculpture has the correct number of ribs. This proves that they had access to X-ray machines, because without X-ray machines this is impossible."

That's when I realized the guy was a kook and it was all rubbish. He was into it for the money, btw. The "click-bait" of the time. And in my opinion Hancock is Däniken's spiritual descendant.