David Dunning, for Ted-Ed, explains the Dunning-Kruger Effect, a cognitive bias in which incompetent people tend to rate themselves as far more proficient than they truly are.
I also find the converse very interesting, experts who think they’re not exceptional. The least & most skilled groups are both incapable of evaluating their own skills.
Dunning also wrote a great piece for Pacific Standard on the phenomenon. To me the standout quote is:
The incompetent are often blessed with an inappropriate confidence, buoyed by something that feels to them like knowledge.
That sure doesn’t sound like anyone I know. Oh, and remember if you think you’re impervious to the Dunning-Kruger Effect, that’s a perfect example of the Dunning-Kruger Effect.