The brain and heart also change. We find a person moved, touched, and shedding tears at the smallest thing that has to do with love or truth, and five years later he may not show any sign of being moved by the greatest joy or sorrow. So also we may find a person very indifferent and cold, and then, three or four years later, he may show a tender and melting state of heart. This depends upon the physical condition of the brain and heart, and this has to do with the subject of physical culture. The Brain and heart may be developed. This is why the zikr and fikr and the various practices of the Sufi are done in connection with the heart. The Sufis give great importance to the cultivation of the heart.