What does it mean when we see a person fail time after time, or another person succeed time after time? It is just a matter of holding the reins of our affairs in our hands. When there is no rein there is failure. Failure means that there has been lack of self control, whether it is a failure in affairs or in health. Illness always comes when a person has lost the control of self. It is because this is the main theme of metaphysics that Hatha Yoga has been considered of the greatest value. All the miracles and all the wonders that have ever been known in this world have been done by those who have been able to control themselves by abstinence, and therefore to control life. However much were said upon this subject, it would still not express it. To begin with a person is puzzled by it, and he wonders whether he should believe it or not. That is why in the East the adepts never speak of their experiences in the spiritual life. They only tell their disciples to lead it and practice for years. "That will make it clear to you", they say.