Every time I see one of my friends his head always down, I ask ‘what's wrong?’ He always says ‘I'm sad’, and I say ‘no! tell me what's going on with you!’ and then he'll say ‘I'm mad!’ It took me some time to think about it, but I figured it out. My friend doesn't know how to express himself. He doesn’t have the words in his vocabulary to tell me, or himself, exactly how he feels. Every feeling has a word that describes that feeling, but he didn't have enough words in his mind to express how he felt in his heart. This is what causes a lot of young men to walk around angry. Reading an audio books will have this problem.