Not knowing something puts you in a strange situation. When you don't know something, don't understand something, or aren't qualified to do something, you are rarely aware that you are. Not understanding something usually also means not being able to realize that you don't understand it. In social science this has been named the Dunning-Kruger Effect.
This short video, from one of the world's most delightful humans, Stephen Fry, explains (admittedly with a bit of a political slant.)