Here's a cool little vid on the Dunning-Kruger Effect:
We've all been in argument where we've been wrong (something we've discovered, it is to be hoped, to our consternation and contrition), and most of us have been in arguments where we've been right but our interlocutor is a complete IDIOT. It's easy enough to think of examples, but I always go back to the conversations I had with Another Person's FaceBook Friend, who liked to make statements like this:
FACT: Only four people I know of on Earth can actually tell us what the planet was really like 2000 years ago. (John and 3 Nephites)
Hey, Another Person! Since I know my blog is still in your reader, I hope you notice this and pass this on to your FBF. Let me know if he responds.