Maybe the real definition of intelligence isn't being able to answer questions effectively, but being able to know what you know and know what you don't know.
There's truth to this, but in a time and place. There are times being very specific about what you know and don't know is important, but most of the time we are learning little by little, and we benefit from saying things we aren't entirely comfortable with, if only to figure out whether they are true and/or socially acceptable.