“It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.” ~ Mark Twain.
A salesman was abducted by an extremely advanced species of aliens one night and subjected to a comprehensive examination on their spaceship. They checked him out physically, and mentally, to learn all they could about human beings. Then before releasing him they allowed the curious earthling to ask them one question. He thought for a moment about the enormity of his responsibility and then asked...
Why Do We Not Learn?
The alien replied ~ "Because you think you already know."