What am I living for?

What am I living for? What is my Purpose? Nearly everyone of us ever asked this question. Well, how couldn't we, if we've been told throughout our whole childhood how important it is to know the answer to the following question: "What do you want to become when you grow up?" A year from know I will have finished the A-Levels, but I still do not know the concrete answer to the question "What do you want to become when you grow up?". But is finding the answer to question really that hard?