On one side, the action of the forces of Yoga hastens the movement of transformation of the being in those parts that are ready to receive and respond to the power that is at work upon it. Yoga, in this way, saves time. The whole world is in a process of progressive transformation; if you take up the discipline of Yoga, you speed up in yourself this process. The work that would require years in the ordinary course, can be done by Yoga in a few days and even in a few hours. But it is your inner consciousness that obeys this accelerating impulse; for the higher parts of your being readily follow the swift and concentrated movement of Yoga and lend themselves more easily to the continuous adjustment and adaptation that it necessitates. The body, on the other hand, is ordinarily dense, inert and apathetic. And if you have in this part something that is not responsive, if there is a resistance here, the reason is that the body is incapable of moving as quickly as the rest of the being. It must take time, it must walk at its own pace as it does in ordinary life. What happens is as when grown-up people walk too fast for children in their company; they have to stop at times and wait till the child who is lagging behind comes up and overtakes them. This divergence between the progress in the inner being and the inertia of the body often creates a dislocation in the system, and that manifests itself as an illness. This is why people who take up Yoga frequently begin by suffering from some physical discomfort or disorder. That need not happen if they are on their guard and careful. Or if there is a greater and unusual receptivity in the body, then too they escape. But an unmixed receptivity making the physical parts closely follow the pace of the inner transformation is hardly possible, unless the body has already been prepared in the past for the processes of Yoga.
[The Mother: CWM 3]