Try to remember something you believed so strongly that your life was completely driven by it -  you thought you will never change or go away from it - and yet today you no longer believe it. It could be an accomplishment, a relationship, a religious or philosophical faith or conviction. Whatever it was, it is a belief. Do you remember having such belief? If you do, then compare that to anything you believe today. Are you more determined today in your current belief than you were in the past? Do you think one day in the future you may actually turn away from what you believe in right now? If you can't remember believing in anything strongly, then what motivated your life in the past? And what motivates your life right now?