The rain follows the plow is the conventional name for the long discredited theory of climatology popular in the American West and Australia during the late 19th century. The theory held that human agriculture makes a permanent change in climate rendering arid regions more humid and more agriculturally productive. The theory was widely promoted in the 1870s as a justification for the settlement of the American Great Plains and South Australia.
The reality is, as records of rainfall indicate, the theory was dreamed up during a brief period of increased rainfall, making the it seem logical. In the U.S. a subsequent return to normal rainfall and the misuse of land by deep plowing and the over grazing of cattle contributed to the disastrous dust bowl.
History is replete with accounts of Native Americans and old timers telling settlers they couldn't count on heavy rainfall every year.
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So the question is why do large groups of people believe things that are just plain crap but makes them feel good when they say them?
"All law is contract law"
"The government is just imaginary"
"Statutes aren't law"
What is it about humans that make them believe and act upon such obvious crap?