The sad truth is that there are more stupid people in the world than smart people. I've come to believe that the Bell curve of human IQ is not symmetrical, but highly weighted towards the dumb end.
I was once in a lecture theatre when the tutor got sidetracked and told us how she could see peoples' auras. Gradually, other students in the room started saying how all of a sudden they could see her
aura. She was darkly lit but standing in front of a bright white board. Apparently these people had made it all the way to adulthood and yet failed to notice the visual after-effect the eye responds with after observing a dark silhouette in front of a bright field.https://en.m.wikipedia.org/wiki/Afterimage
No, these people weren't kidding around.