The world we live in is filled with people who come from different backgrounds and grew up with a different line of thoughts and mannerisms. Obviously, this will affect the way people treat each other. Some people treat people good while others treat people in a bad way.
Nevertheless, whichever way you treat people is up to you.
All in all, one thing certain is that when you dish out ill treatment to people, be rest-assured that time will come when you will have a taste of your own medicine. Payback time is something nobody can run away from no matter how smart you think you are in life.
Learn to live by the golden rule; do unto others as you will have them do to you.