If TV has taught me anything, it's that to correctly motivate yourself in the fighting arts it is necessary for you to have a rival to fight to the death. It isn't too hard to find one; simply ask yourself this question? What relative (preferably a father or brother) died recently who's death I can avenge?
It also seems to help if you drop to your knees and scream "Noooooooooooooooooo!" in preparation.