Pythagoras (from the theorem) created his own cult with crazy severe dietary restrictions.
Pythagoreanism was the system of esoteric and metaphysical beliefs held by Pythagoras and his followers, the Pythagorean cult. Pythagoreanism originated in the 5th century BC and greatly influenced later philosopers, such as Plato.
The Pythagorean code heavily restricted the diet of it's followers, prohibiting the consumption or even touching of any sort of bean. Some believed that this was due to their belief in the soul, and the fact that beans have the ability to create life.
Others belive that beans were forbidden because they resemble the kidneys and genitalia. But the most likely reason for the rule is some magico-religious explanation, such as the belief that beans and human beings were created from the same material.