Ancient Persian wisdom

"One who knows and knows that he knows. This is a man of knowledge; get to know him! One who knows, but doesn't know that he knows. This is a man who's unaware, so bring it to his attention. One who doesn't know, but knows that he doesn't know. This is an illiterate man; teach him! One who doesn't know and doesn't know that he doesn't know. This is a dumb man; and would be dumb forever!"