More extracts from that same podcast:

In each case, right up until the moment I received evidence to the contrary, all this misinformation, these supposed facts, felt true to me. I had believed them for decades and I had accepted them in part because they seemed to confirm all sorts of other ideas and opinions floating around in my mind. Plus they would have been great ways to illustrate complicated concepts, if not for the pesky fact that they were, in fact, not facts.

That's one of the reasons why common misconceptions and false beliefs like these spread from conversation to conversation and survive from generation to generation and become anecdotal currency in our marketplace of ideas. They confirm our assumptions and validate our opinions and, thus, they raise few skeptical alarms. They make sense and they help us make sense of other things.

I don't think there's a time when everyone knows something