When you have seen a little glimpse that you are the creator of your own misery, it will be very difficult for you now to go on creating it. It is easy to live in misery when you know others are creating it -- what can you do? You are helpless. That's why we go on throwing responsibilities on others.
There are people who think they are in misery because of past karma, past life karma.
The whole idea is so foolish: put your hand in the fire now and you will be burned next life. Life is immediate. That's what life is -- immediacy. Life never postpones. You do something beautiful, and in that very doing you are rewarded; not that you will have to wait many lives for the reward. You do something ugly, and in that very act is the punishment; the punishment is not separate from the act.