After Lord Krishna had killed Kansa, He made his grandfather, Ugrasena, the king of Mathura. Then, Lord Krishna and Balarama went through a sacred thread ceremony called Yajna-pavitra. Earlier, all students lived and learnt in gurukul. So, Lord Krishna and Balarama, too, left for the gurukul of Sage Sandipani, who lived in Kashi. Lord Krishna and Balarama had killed many demons and earned universal fame. Even then, they followed their guru’s commands obediently and humbly. They went to the forest every day and brought firewood. They helped Guru Mata, Sage Sandipani’s wife, cook food in the ashram. Sage Sandipani was pleased with their humility, modesty and intelligence. Lord Krishna and Balarama read spiritual Vedas like Rig, Yajur, Sama and Atharva, the Upanishads, and worldly knowledge like kalpa, jyotisa or astrology, and vyakarana or grammar. They also became proficient in archery, politics and sixty-four arts in sixty-four days. ‘They memorise everything so fast!’ thought Sage Sandipani, astonished at their fast progress and development.