I think a lot of people are acting the way they think other people are acting and because of the world we have built for ourselves and the lack of trust possible due to a spiralling of selfish behaviour, it makes it a self-fulfilling prophecy.
This is just the truth. Most people do things or act in a way cos they think if the other person is in their position, the person will also act the way they acted or even do more. The major problem is taking one's self thinking to be right, which in most cases is always wrong.
We should all act irrespective of people's actions or what will think people will do or are doing. We all should be ourselves following the right principles