Only the ignorant think they know everything about anything.
Good teaching always results in two things for the student, increased knowledge of the subject matter accompanied by a proportional knowledge of the degree of the student’s ignorance thereof. This is essential to lifelong learning because while the first produces the second, it is the second that motivates the first.
Aristotle’s Ethics begins with the following,
Every art, and every science reduced to a teachable form, and in like manner every action and moral choice, aims, it is thought, at some good: for which reason a common and by no means a bad description of the Chief Good is, “that which all things aim at.”
My first thought was why is the clause “reduced to a teachable form” even necessary? Every art and science should be reduced to a teachable form. Of what value is art or science if it is not taught? A teacher’s raison d’être is to confer knowledge and understanding. A teacher’s job is never done as long as ignorance and misunderstanding exist. Today’s teachers worry about getting tenure for security. A teacher’s security should be based on how well that teacher eliminates ignorance and corrects misunderstanding.
I am convinced of only a very few things, one of which is; as my knowledge expands, I become increasingly aware of my ignorance.
A stupid person lacks knowledge because of a limited ability to learn whereas an ignorant person lacks knowledge because of a limited desire to learn. The former has a reason for not knowing while the latter merely has an excuse. Excuses are like asses. Everybody has one and it stinks when they use it.