When a balloon (longer one not the round one) is filled with air, it erects upright, and if the same balloon is filled with Water, it bows down.
Exactly the same way, a person without knowledge will always be more egoistic, having a rod in his neck to remain uptight, more vocal and not willing to listen, start fighting when failing in an argument. Being egoist and empty inside, he will try to portray himself as if he knows everything and rest of the others are dumb.
Its like when an empty glass is hit with a spoon, it sounds but the same glass when filled with water does not give sound, when hit by a spoon. A knowledgeable person is like a glass filled water, so he does not tell everyone that he has knowledge, whereas a person without knowledge always portrays himself as knowledgeable by talking loud in front of the gathering.
Whereas a person with knowledge will always be humble, willing to listen and show humility while interacting with people. Will always be helping and kind to people around him.
Actually it is him, who is supposed to be portraying himself as being knowledgeable but it is always contrary to, what is the norm and that’s what makes him UNIQUE, which is one of the characteristic of Almighty Allah.