Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 4
The headache if it comes is only a result of the body not being accustomed to the pressure or else to some resistance there. The difficulties of course rise up, but it is not always in the 
beginning. Sometimes the first effect is such that one feels as if there were no difficulties,– they rise afterwards when the exultation wanes and the normal consciousness has a chance to assert itself against the flood of power or light from above. There is a resistance that has to be fought out or worked out – fought out if the nature is unsteady or resists violently, worked out if the will is steady and the nature moderate in its reactions. On the other hand if there has been a long preparation and the resistances of the nature have been already largely dealt with by the psychic or by the enlightened mental will, then there are no primary or later aggravations but a steady and quiet pulsing of the change, the remaining difficulties falling away of themselves as the new consciousness develops, or else there may be no difficulties at all, only a necessary readjustment and change.