Instinct ??

There are 4 types of person in this world : 1. The person who knows, and knows that he knows. He is wise, so consult him. 2. The person who knows, but doesn't know that he knows. Help him not forget what he knows. 3. The person who knows not, and knows that he knows not. Teach him. 4. Finally, there is the person who knows not but pretends that he knows. He is a fool, so avoid him.