Or “You have to know something about a subject to realize you don’t know very much about it.”
Open up social media or flip on the news, and you will inevitably come across someone who genuinely believes they have the expertise to speak with authority on a topic which they actually seem to know almost nothing about.
This may not be a simple case of gross overconfidence. Knowledge or skill in a particular area can be necessary to understand the extent and limits of one’s abilities. So goes the reasoning behind the Dunning-Kruger effect, the inclination of unskilled or unknowledgeable people to overestimate their own competence.
The effect has been reported in many different tasks and specialized fields of knowledge related to healthcare, safety procedures, education and even social issues, like racism and sexism. It appears in the general population as well as in groups of people with shared interests or professions.