Why does the disclosure timeline always start at Roswell when basically every culture has some version of "beings from the sky taught us something"?

Been thinking about this a lot. Every disclosure timeline I see starts in 1947 like that's when this whole thing began. But if you actually look at oral traditions, mythology, ancient texts, basically everywhere, there's some version of "something not human showed up and gave us knowledge." Feels like we keep treating this as a Cold War era phenomenon when the actual pattern is way older and way more global. Anyone else notice this or am I overthinking it?