So if you train up... You have got this facility of life, comfortable life. Do not misuse it for becoming next life a dog. Utilize it to become next life God. That is success. You have got advanced intelligence, but this intelligence is given to you for understanding God and your position that by forgetting God you are in this material world, and in this material world you are changing one body to another. Sometimes American body, sometimes demigod's body, sometimes celestial body, sometimes dog's body, cat's body, tiger's body. This science is unknown. But this is the science. Prakṛteḥ kriyamāṇāni guṇaiḥ karmāṇi sarvaśaḥ ahaṅkāra (BG 3.27). We have got this body, that body, this body, under the direction of the prakṛti, material nature. So therefore intelligence is that "If I am eternal..." Na hanyate hanyamāne śarīre (BG 2.20). You are not dying. Hanyamāne śarīre.
That you can experience practically, daily. How is that? When you sleep at night, then you dream, means subtle body. So these activities of this gross body stop. You again work in the subtle body. You dream that you have gone to somewhere or in the forest or somewhere, somewhere, somewhere. But you forget that "My real body is lying in this bed." You do not remember. This is practical. So I change this, myself. I am soul. I change from this gross body lying on bed in a very nice apartment, skyscraper building, but I have gone to the forest, and I am affronting a big tiger and I'm crying. In this bed I am crying. The friends say, "Why you are crying?" "Tiger, tiger, tiger." Where is tiger? This is called subtle body. So you are changing daily at night from this gross body to the subtle body. And again the dream is over, from the subtle body, again to the gross body. Every one of us has got this experience.