A living being has different activities in the different stages of life. One stage is called jāgrata, or the life of awakening, and another is called svapna, or the life of dream. Another stage is called suṣupti, or life in an unconscious state, and still another stage occurs after death.
Puranjana used to live with his wife for sense enjoyment, and at night this sense enjoyment was actuated in different ways. A man sleeps very soundly when he is greatly fatigued. When a rich man is greatly fatigued he goes to his garden house with many female friends and there plays in the water and enjoys their company. Such is the tendency of the living entity within this material world. A living entity is never satisfied with a woman unless he is trained in the system of brahmacarya. Generally a man’s tendency is to enjoy many women, and even at the very end of life the sex impulse is so strong that even though one is very old he still wants to enjoy the company of young girls. Thus because of the strong sex impulse the living entity becomes more and more involved in this material world.
Since the body is a great city, there must be various arrangements, such as lakes and gardens, for sense enjoyment. Because the body has genitals, when the living entity attains the right age—be he man or woman—he becomes agitated by the sex impulse. As long as one remains a child, he is not agitated by seeing a beautiful woman. Although the sense organs are present, unless the time is ripe there is no impulsion for sex. The favorable conditions surrounding the sex impulse are compared here to a garden or a nice solitary park. When one sees the opposite sex, naturally the sex impulse increases. It is said that if a man in a solitary place does not become agitated upon seeing a woman, he is to be considered a brahmacārī. But this practice is almost impossible. The sex impulse is so strong that even by seeing, touching or talking, coming into contact with, or even thinking of the opposite sex—even in so many subtle ways—one becomes sexually impelled. Consequently, a brahmacārī or sannyāsī is prohibited to associate with women, especially in a secluded place. The śāstras enjoin that one should not talk to a woman in a secret place, even if she happens to be one’s own daughter, sister or mother.
The reason is the sex impulse is so strong that even if one is very learned, he will become agitated in such circumstances. If this is the case, how can a
young man in a nice park remain calm and quiet after seeing a beautiful young woman?
— Śrīmad-Bhāgavatam (Bhāgavata Purāṇa) » Canto 4: The Creation of the Fourth Order » Chapter 25. The Descriptions of the Characteristics of King Puranjana, Verse: 44 and 17, Purport.