Unfortunately it spawned the hard-to-dispel myth that people of the past actually believed the world was flat

I am embarrassed to say that I didn't know it was a myth until just a few years ago. Had trouble convincing my DH about it until we were in the Hudson Valley and visited Irving's house where some guide mentioned it. It does say something about myths, how people latch on to them. I wonder what comes first - the world view of superiority to a time period or people, or the myths that support it?