This explains a lot.
Why Stupid People Think They're Smart [The Dunning-Kruger Effect]
ow knowledge works and why stupid people think they're smarter than the smart people who think they're stupid.
https://www.youtube.com/watch?v=TT81fe2IobI
Quote:The Dunning–Kruger effect is a cognitive bias in which people with limited competence in a particular domain overestimate their abilities. Some researchers also include the opposite effect for high performers: their tendency to underestimate their skills.