"Unpredictable"

Every one of us has a bad side whether we like it or not. More often than not people are mean, rude and it hard to understand. Why do unpredictable people or moody individuals are hard to deal with? Is it because they couldn't express their feelings or can't speak their mind? Or is it because they are just the way they are? Well, In my opinion, they are the person that has also difficulty in dealing with themselves. How can we help them? Are they need help? I don't think so. They know that they are unpredictable. I'm pretty sure they are being told. Someone advise them. They don't need help. They can actually change if they like to. What they do is that they are following what they feel, how they feel. They don't think about other people's feelings.
I know a few, and for me, that is very hard to deal with because you don't when you enter, when you gonna blow you jokes. You are hesitant to say something. what you did is to keep your mouth SHUT. I always deal with that kind of attitude.