It is a reflection of the real world. People will pick and choose who they want to associate with. It is best to be unconcerned. Each person will draw their own friends. One way of looking at it is, those who reject you are not worth knowing. There is something hidden within them that is unpleasant. In that way they did not waste your time with their dishonesty. You can move on to better people. In life, the ignorant people will always let you know who they are by their rude behavior. If you are detached and don't care what they think, you will remain happy and serene regardless of their opinions or attitudes.