There is, out there, a very old science fiction story about a cultivar of coffee that did the same thing; I read it over 40 years ago and have never been able to find it since. It may not even have been in English, I can't recall. At one point it makes its way into the halls of Congress or the United Nations or some such institution, and at once one of the delegates stands up and shouts "It's all balls!" A new era of logic and reason ensues. It was very similar to Clifton Marks' story "The Conqueror," which involved dahlias instead of coffee. A pity no such substance has ever been isolated; what is clear is that from now on, PHB will shun dark chocolate, preferring to live in his world of cognitive dissonance.