Why stupid people think you’re stupid 

So there's this thing called the Dunning-Kruger effect:

A cognitive bias in which “people reach erroneous conclusions and make unfortunate choices but their incompetence robs them of the metacognitive ability to realize it”. The unskilled therefore suffer from illusory superiority, rating their own ability as above average, much higher than in actuality; by contrast the highly skilled underrate their abilities, suffering from illusory inferiority.

[Researchers] hypothesized that with a typical skill which humans may possess in greater or lesser degree,

  1. Incompetent individuals tend to overestimate their own level of skill.
  2. Incompetent individuals fail to recognize genuine skill in others.
  3. Incompetent individuals fail to recognize the extremity of their inadequacy.
  4. If they can be trained to substantially improve their own skill level, these individuals can recognize and acknowledge their own previous lack of skill.

Via bobulate and Caterina Fake.