Quote in context:
Suppose, though, your good fortune does buy you happiness: you have no complaints. Yet you must complain. Your continued happiness hinges on your fulfilling the complaint requirement. Happiness uncomplained about provokes the gods, and surely the evil eye of your neighbors. Thus the Yiddish “no evil eye” (kein erin harah), upon hearing good news. Good news is dangerous stuff; it is a tax on your remaining supply of good luck. Best to protect against the harmful consequences of good luck and ward oil the demons by knocking on some nearby wood. Beware, too, the envy of your neighbors. it is one of mankind’s most predictable traits to find as much cause for complaint in another’s good fortune as in one’s own misfortune. The former being experienced as a special case of the latter. In a world in which one’s standing is gauged relative to others and the competition is fierce, your good fortune costs your neighbors. They will, unless you go out of your way to make their envy less painful to them, plot to make your happiness painful to you. As the Bemba proverb says: “To find one beehive in the woods is good luck, to find two is very good luck, to find three is witchcraft.” If your luck is too good to be true, it might cost you your life.
