Suppose if I get the body of a dog, then my occupational duty will be "Gow! Gow!" Because according to the body the duty is changed. So these occupational duties, they are not permanent. But I am eternal, na hanyate hanyamāne śarīre (BG 2.20). By the destruction of this body, I am not destroyed. I remain, I simply enter another body. I, as spirit soul, I remain. Just like I'm entering different bodies in this life. I was a child, I enter another body.
Just like this small child, Sarasvatī. According to the body, she is acting. She's acting sometimes nonsense, but we take it delight, because she is child. But the same nonsense if I do in another body, a grown-up body, that will be ridiculous. In this child body, she is naked, but people enjoy it. But when she is grown up and she is ladylike, she is young girl, if she becomes naked, oh, that is ridiculous. So here in this life also we see according to the change of the body, the duty is changing, the activities are changing.
So, this body is changing, that's a fact. Tathā dehāntara-prāptiḥ dhīras tatra na muhyati (BG 2.13). Just like in this life we are changing different types of bodies, similarly, dehāntara-prāptiḥ, another body. These rascals, they do not understand the simple reasoning. Simple logic they cannot understand—still they argue, "What is the proof there is transmigration of the soul?" Here is the proof. Now this child, Sarasvatī, when she is a grown-up lady she'll not act like that. But everyone will accept her, Sarasvatī, the same character. Her father, mother, relatives, everything there: Sarasvatī has got another body.