So here's something I wonder about: Lets say there was some outbreak of a disease that made every person being born dumber and crazier than the ones born the day before that and so on and this went on very gradually over a period of decades.

How the fuck would anyone even know? Like, at what point does a nation of ass-picking apes look at the smaller ones and decide, "Gee, that seems odd."

I mean, what would it look like? Would they just wake up one day and wander around an airport full of rusted planes on the ground and assume they are giant dead metal birds? Does everyone just start praying to thunderstorms or trying to talk to trees or something? How stupid would humans get before just forgetting there was ever any such thing as humans?