Dhīra and adhīra, there are two classes of men. One is sober, even there is cause of agitation, still he remains firm. He is called dhīra. And adhīra means as soon as there is cause of agitation, he became a victim. That is called adhīra. So we have to become dhīra. We have been adhīra in so many different forms of life, because I am coming to this human form of life after evolution of 8,000,000 forms of body. Jalajā nava-lakṣāṇi sthāvarā lakṣa viṁśati (Padma Purāṇa). That is evolution. So after . . . bahu sambhavānte (SB 11.9.29). After many, many years I have got this opportunity. In other, lower animal life, I have enjoyed the senses in so many ways. So sense enjoyment is not very difficult. Even there . . . viṣayaḥ khalu sarvataḥ syāt (SB 11.9.29). The hogs and pigs, they have got facility for sense enjoyment. They do not care even who is who. Even she is mother or she is sister or she is daughter, they will enjoy sex. That is hog life. You have seen. There is no discrimination. The monkeys, they are enjoying sex life. So everyone enjoys sense life.
So "Why? I have got this valuable life, human form of life. Why I shall become a living entity like hogs and dogs?" This is called tapasya. "Why I shall become hogs and dogs and again I shall put myself in the cycle of birth and death? I have got this life after so many evolutionary process. Why not practice little tapasya in this life?" This is knowledge. "If by practicing little tapasya, restraint, I can get relief from this repetition of birth and death, why shall I not do it?" This is knowledge. And if I again become victimized . . . the laws of nature is there. If you want, you can enjoy. Nature will give you: "All right, you want so much sex. All right, come on, become a hog. Yes." (laughter) So nature is ready. It is not very difficult. Therefore the śāstra says, "No, no, no. This life is not for becoming a hog and dog." Nāyaṁ deho deha-bhājāṁ nṛ-loke kaṣṭān kāmān arhate viḍ-bhujāṁ ye (SB 5.5.1).
The whole world is working so hard. They are going to the office; they are going to the . . . working hours to earn livelihood. But what is the pleasure? The pleasure is sex. That's all. Their ultimate goal is sex. Yan maithunādi-gṛhamedhi-sukhaṁ hi tuccham (SB 7.9.45). So one should consider, "The sex indulgence is given to the hogs and dogs, and for the same enjoyment I'll have to work so hard?" This is knowledge. "For same enjoyment?" I have got this human form of life for understanding Kṛṣṇa, for understanding God, my position, what I am. I am not this body. I am spirit soul. I have been put into this body, and because I have been put into this body—the body is material—it must finish. It must be finished. Anything, it has got six changes. Anything material, it has got birth, it has got growth, it has got after-effect, then dwindles, and then finished—everything, anything you take, the material. This is called ṣaḍ-vikāra, six kinds of changes. So I am eternal. Na hanyate hanyamāne śarīre (BG 2.20). I do not die after this body is finished, and again I will have to . . . tathā dehāntara-prāptiḥ (BG 2.13). So this is knowledge. One has to always think of this. That is called tapasya.