Memes

Some, yes, but many of the things that Europeans go "whoa how could they have possibly done that" (waterworks, roads, pyramids) when the Romans or people adjacent to the Romans were able to do it 1000+ years earlier. Not trying to do the whole "primitive" bit, more just saying that a lot of the shit white people say was "impossible" from brown people of their era was achieved by people they considered white thousands of years earlier. Logically speaking, there is no reason that indigenous people wouldn't have been able to figure out many of the things white people credit to aliens.