“Coined in 1999 by then-Cornell psychologists David Dunning and Justin Kruger, the eponymous Dunning-Kruger Effect is a cognitive bias whereby people who are incompetent at something are unable to recognize their own incompetence. And not only do they fail to recognize their incompetence, they’re also likely to feel confident that they actually are competent.” ~ Mark Murphy
More on the Dunning-Kruger Effect here.