The pain which has passed away has been spent up by experience. It cannot, therefore, fall within the sphere of avoidable. And that which is present, is being experienced at the time of its existence; it cannot, therefore, be considered as the avoidable with reference to the future movement of time. Hence that pain alone which has not yet been experienced, troubles the Yogi who is sensitive as the eye-ball; it does not trouble any other knower. Hence that alone is avoidable pain.