People and incidents always happen in life and they all are a result of certain actions. As newton says "every cause has an affect".
So people come and they come for a purpose in your life. Not only you learn from them, but sometimes they come in your life because they are meant to learn something from you and then move on. I mean if you immagine, everyday how many people we come in touch with and how many different people we talk to, and most of those people we never see again. Life is a journey, not a destination and people and places in a journey are temporary untill you reach your destination.
Life is a story and we are writing one page at a time. Everyday we start a new page. But you see, what i think most of the times? How would you like your story to be ended? I mean when people read the book of your life, would there be good things for them to read? Would you like your story to have a happy ending? Would your story be worth reading even?
You see we all talk about destination, but who picks our destination? Is it preset? or can we chose it ourself?