Fools, Students, the Sleeping and the Wise

For some reason, I was thinking of this ancient proverb today:

He who knows not and knows not that he knows not is a fool; avoid him.

He who knows not and knows that he knows not is a student; teach him.

He who knows and knows not that he knows is asleep; wake him.

He who knows and knows that he knows is a wise man; follow him.