One of the problems with all of this is that not all narratives are equal. Imagine, to take a silly example, that someone told you story after story extolling the virtues of eating dog shit. You've been told these stories since you were a child. You believe them. You eat dog shit hotdogs, dog shit ice cream, General Tso's dog shit. Sooner or later, if you are exposed to some other foods, you might figure out that dog shit really doesn't taste good. Or if you cling too tightly to these stories (or if your enculturation is so strong that dog shit actually does taste good to you), the diet might make you sick or kill you. To make this example a little less silly, substitute the word pesticides for dog shit. Or, for that matter, substitute Big Mac, Whopper, or Coca Cola.