Mean people

I have never understood mean people. Not only do I not understand mean people but they frustrate me. I have had a few interactions with people lately that were not very positive and writing is my way of making sense of the world. (Interesting choice of words, Sally, in a recent interview I did with a professional singer, he said music was his way of making sense of the world.)I don't understand why a person needs to be mean to another. I don't know how people can live with themselves when they damage others with their words? Do we not realize that humans are sensitive and how easy sweet, kind words are? Why do we not seek to uplift others with our actions and our words?I came across this passage in Paulo Coelho's book The Winner Stands Alone. If you are not familiar with Coelho's work, he is a novelist who typically writes magic realism stories. His most popular book is The Alchemist and I highly recommend it. Anyhow, he says,

“How people treat other people is a direct reflection of how they feel about themselves.” -Paulo Coelho

We hear this notion often, people who are mean are intimidated, threatened, insecure, etc. But I really struggle with believing that this many people can suffer from those things. Maybe so. But I still can't get over it. Is being mean a defense mechanism? Do some people know how to be polite because they were raised to be that way?Can we please not be mean? Can we use our words to convey our emotions---hurt, anger, frustration, happiness, excitement, anticipation---rather than react without thinking and hurt those we love and even those we don't know?