Have you ever taken a second to step back and look at you life. You see all the mistakes and achievements you've made up to this point. Things you've done wrong, people who have wronged you.
Then, have you ever really thought about your life? Your life, not anyone else's, just your own life and your own actions and things that have happened to you.
Doesn't it suck when you do this and think, "What in the hell am I doing with my life?!"
What's worse, is when you realize this, but can do nothing to change it. That particular realization rots and eats at you until you are free of your bonds and you actually have the chance to change how you live your life. Until then, well, try not to let these realizations eat you alive.