Now, we can see in our front, there is a tree standing for many years, and he has to stand in scorching heat, torrents of rain, pinching cold. He cannot move an inch. And if we think seriously, "Suppose if I would have been put into that condition, that 'Stand up here for five hundred or five thousand years. You cannot move an inch, and you bear all the sufferings, scorching heat, storm,' " would I agree to do that? No. I will not agree. But the tree is also a living entity. He is a living being. I am also living being. So I am put in a different condition of life and the tree is put in a different condition of life. Why? Why this distinction? Is there any upper hand superior judgment that one is put in the condition of standing tree and one is put in the beautiful human body, freely moving? There must be, because we are all living entities. We are all soul, spirit soul. We are simply put in different dresses.
Therefore, in the beginning of the instruction of Bhagavad-gītā, this lesson is the first lesson. We have to understand.
dehino 'smin yathā dehe
kaumāraṁ yauvanaṁ jarā
dhīras tatra na muhyati
Ninety-nine point nine percent, they do not understand this philosophy, especially in the modern age. Mandāḥ sumanda-matayo [SB 1.1.10]. They are very, very dull rascals. This is the challenge. Mandāḥ. Mandāḥ means dull, no intelligence. A simple truth, Kṛṣṇa is explaining to Arjuna. It is authoritative statement because Kṛṣṇa says, and Kṛṣṇa says not unreasonably, very reasonably, "I am giving very common example that smin dehe, within this body, the proprietor of the body or the spirit soul is there. And on account of this," dehino 'smin yathā dehe [Bg. 2.13], "because the living entity is within this body, therefore the bodily changes are taking place." What is that changing? Dehino 'smin yathā dehe kaumāraṁ yauvanaṁ jarā. "The body is sometimes child, and sometimes boy, sometimes young man, sometimes old man. So the body is changing." Who cannot understand this? The child, the small child, is dancing. Now, that child will get the body of a young man like you. Everyone knows it. This body will change. Where is the difficulty? And Kṛṣṇa is giving this common example, tathā dehāntara-prāptiḥ [Bg. 2.13]. As you are experiencing this change of body, similarly, you take it that this body also will change. An old man like me, the next body is there. Either farther old man or, after death, another body. This is to be understood. Tathā dehāntara-prāptiḥ. Dehāntara-prāptiḥ means to get another body.
So we are experiencing in our this life. It is taking change so swiftly that we cannot understand how the body is changing, but it is changing. So similarly, this body will change. Tathā dehāntara-prāptiḥ. And we have to change that body after death according to my mental condition because we have got two bodies, the subtle body and the gross body. This gross body is finished; it is no more working. Just like at night the gross body does not work. We are thinking, "I am sleeping." Sleeping means the body is so much tired, it is no more working. But your another body, which is made of mind, intelligence, and ego—subtle body—that is working. Everyone has got this experience. The subtle body takes you to another place or another condition. You are dreaming that you have gone to the jungle. You are meeting some animals. The tiger is there coming to attack you, and you are crying, "Here is tiger! Tiger! Tiger!" And the man who is not dreaming, he says, "Where is tiger? Why you are crying?" But he's actually... The result is there. Don't think that the result is not there. In dream you are thinking your lover is there, you are embracing, and you get discharge, not that that you are not working and it is not, there is no result. There is result. I cannot see what is the result, what you are dreaming. I am fool. I do not know. But the man who is dreaming, he is experiencing. Similarly, change of body means we are carried by the subtle body to another gross body. This is the process, nature's way. You cannot say that "I will not change body." No, you will be forced. Just like a young man can say, "I will not become old man." No, nature will force you to become an old man, or change your body. This is the law of nature. You cannot surpass the laws of nature. Similarly, change of body, that is forced by the nature. Prakṛteḥ kriyamāṇāni guṇaiḥ karmāṇi sarvaśaḥ [Bg. 3.27]. Prakṛteḥ, by the nature's law, we have to do. We are completely under nature's law. And we are declaring independence. This is our foolishness. This is our foolishness.
Srila Prabhupada, Lecture on Srimad-Bhagavatam 6.1.7 -- Honolulu, June 15, 1975