This is the material world. There are 8,400,000 types or forms of this material body, and we are wandering, sarva-gata, in different planets, in different forms. This is material world. And in the material world, whatever form we may have, we have got attachment for this body. Not only attachment, we are under the impression that "I am this body." Everyone. That is material conception of life.
So that thing happened to Arjuna. In the battlefield, he identified himself as the body. He thought himself that he belongs to the Kuru family, and his family relatives, his, other side, his brother, nephews, or his grandfather... So he refused to fight. "My dear Kṛṣṇa..." After placing the chariot between the two parties, senayor ubhayor madhye rathaṁ sthāpaya me acyuta (BG 1.21). And then he become very much disturbed that "I have to kill the other side, my brother and my nephews, my grandfather. No, no. Kṛṣṇa, I cannot. No. This is not possible. I shall not fight." This is the stage of Bhagavad-gītā. Kṛṣṇa became very much dissatisfied. Of course, Arjuna played the part of a conditioned soul. A conditioned soul is under the impression that he's the body. That is animal life.