They learned practical psychology—how to influence another’s mind and thus induce another to act according to one’s own desire. Sometimes this is called hypnotism. They learned how to wash hair, dye it different colors and curl it in different ways. They learned the art of telling what is written in someone’s book without actually seeing it. They learned to tell what is contained in another’s fist. Sometimes children imitate this art, although not very accurately. One child keeps something within his fist and asks his friend, “Can you tell what is within?” and the friend gives some suggestion, although he actually cannot tell. But there is an art by which one can understand and actually tell what is held within the fist.
Kṛṣṇa and Balarāma learned how to speak and understand the languages of various countries. Not only did They learn the languages of human beings; Kṛṣṇa could also speak even with animals and birds. Evidence of this is found in the Vaiṣṇava literature compiled by the Gosvāmīs. Then They learned how to make carriages and airplanes from flowers. It is said in the Rāmāyaṇa that after defeating Rāvaṇa, Rāmacandra was carried from Laṅkā to Bhārata-varṣa on a plane of flowers, called a puṣpa-ratha. Kṛṣṇa and Balarāma then learned the art of foretelling events by seeing signs. In a book called Khanara-vacana, the various types of signs and omens are described. If when one is going out one sees someone with a bucket full of water, that is a very good sign. But if one sees someone with an empty bucket, it is not a good sign. Similarly, if one sees a cow being milked alongside its calf, it is a good sign. The result of understanding these signs is that one can foretell events, and Kṛṣṇa and Balarāma learned the science. They also learned the art of composing mātṛkā. A mātṛkā is like a crossword box, with three numbers in each row. If one adds any three from any side, it will come to nine. The mātṛkās are of different kinds and for different purposes.
Kṛṣṇa and Balarāma learned the art of cutting valuable stones such as diamonds, and They also learned the art of questioning and answering by immediately composing poetry within the mind. They learned the science of the action and reaction of physical combinations and permutations. They learned the art of a psychiatrist, who can understand the psychic movements of another person. They learned how to satisfy one’s desires. Desires are very difficult to fulfill; but if one desires something which is unreasonable and can never be fulfilled, the desire can be subdued and satisfied, and that is an art. By this art one can also subdue sex impulses when they are aroused, as they are even in brahmacārī life. By this art one can make even an enemy one’s friend or transfer the direct action of a physical element to other things.
Lord Kṛṣṇa and Balarāma, the reservoir of all knowledge, exhibited Their perfect understanding of all the arts and sciences mentioned above. Then They offered to serve Their teacher by awarding him anything he desired. This offering by the student to the teacher or spiritual master is called guru-dakṣiṇā. It is essential that a student satisfy the teacher in return for any learning received, either material or spiritual. When Kṛṣṇa and Balarāma offered Their service in this way, the teacher, Sāndīpani Muni, thought it wise to ask Them for something extraordinary, something no common student could offer. He therefore consulted with his wife about what to ask from Them. He and his wife had already seen the extraordinary potencies of Kṛṣṇa and Balarāma and could understand that the two boys were the Supreme Personality of Godhead. They decided to ask for the return of their son, who had drowned in the ocean near the shore at Prabhāsa-kṣetra.
When Kṛṣṇa and Balarāma heard from Their teacher about the death of his son, They immediately started for Prabhāsa-kṣetra on Their chariot. Reaching the beach, They asked the controlling deity of the ocean to return the son of Their teacher. The ocean deity immediately appeared before the Lord and offered Him all respectful obeisances with great humility.
The Lord said, “Some time back you caused the drowning of the son of Our teacher. I order you to return him.”