It is possible to live one's life aimlessly, not knowing at all what we are here for on this planet earth. We all know it very well that man is not destined to live forever on this earth. We've seen people dying and we know that our time will come one day. It is, therefore, crucial to stop at one point of our life and take time thinking about our purpose of being here, what or who can make a difference in our lives, how we can make a difference in others' lives and even about life after death!
I am presently reading one book called Purpose Driven Life by Rick Warren. Christian or no Christian, I am sure it can be of help to you to understand what on earth you are here for? You can either ask for a copy of the book from a bookstore or check the website to read the first seven chapters of the book at http://www.purposedrivenlife.com/
I wish you all the best!!!