Happiness?

What is happiness? I doubt i have any answers, because happiness changes from person to person so there cannot be any particular definition for it. What can be happiness for me can be the cause of misery for someone else. For me happiness is something which can be felt only by you, no one else will be able to understand it. Even your family & best friends. Though people say that happiness cannot be measured the fact is, it is the most measurable entity. Lets begin from your childhood, you get your first birthday gift you are happy. You go to school make friends, get new school books, uniform, you are happy. Then comes college, the life with all care free attitude, you are happy at that time because you have friends, girl friends, your needed are fulfilled by the pocket money provided by your parents, but you are happy. Life moves ahead you get married, have progenies then you are happy to see them growing. Now, tell me have you really been happy? No you just lived your life. If you feel your happy then share the happiness with me.