I was reading through a mostly uninteresting book by William Ophuls called Immoderate Greatness—Why Civilizations Fail. Right there near the beginning, in the "Biophysical Limits" section, at the beginning of the "Exponential Growth" chapter, was physicist Al Bartlett's famous quote.
The greatest shortcoming of the human race is the inability to understand the exponential function.
NO, NO, NO! Humans (including economists) DO understand the exponential function.
The problem is they don't think it applies to them.