SB 4.29.68
sarve kramanurodhena
manasindriya-gocarah
ayanti bahuso yanti
sarve samanaso janah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The mind of the living entity continues to exist in various gross bodies, and according to one’s desires for sense gratification, the mind records different thoughts. In the mind these appear together in different combinations; therefore these images sometimes appear as things never seen or never heard before.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The activities of the living entity in the body of a dog may be experienced in the mind of a different body; therefore those activities appear never to have been heard or seen. The mind continues, although the body changes. Even in this life span we can sometimes experience dreams of our childhood. Although such incidents now appear strange, it is to be understood that they are recorded in the mind. Because of this, they become visible in dreams. The transmigration of the soul is caused by the subtle body, which is the storehouse of all kinds of material desires. Unless one is fully absorbed in Krsna consciousness, material desires will come and go. That is the nature of the mind — thinking, feeling and willing. As long as the mind is not engaged in meditation on the lotus feet of the Supreme Personality of Godhead, Krsna, the mind will desire so many material enjoyments. Sensual images are recorded in the mind in chronological order, and they become manifest one after another; therefore the living entity has to accept one body after another. The mind plans material enjoyment, and the gross body serves as the instrument to realize such desires and plans. The mind is the platform onto which all desires come and go. Srila Narottama dasa Thakura therefore sings:
guru-mukha-padma-vakya, cittete kariya aikya,
ara na kariha mane asa
Narottama dasa Thakura advises everyone to stick to the principle of carrying out the orders of the spiritual master. One should not desire anything else. If the regulative principles ordered by the spiritual master are followed rigidly, the mind will gradually be trained to desire nothing but the service of Krsna. Such training is the perfection of life.