Everything depends on bhagavān, or ajaḥ, the unborn. Why doesn’t one please Bhagavān to receive a better body? The answer is ajñas tamasā: because of gross ignorance. One who is in complete darkness cannot know what his past life was or what his next life will be; he is simply interested in his present body. Even though he has a human body, a person in the mode of ignorance and interested only in his present body is like an animal, for an animal, being covered by ignorance, thinks that the ultimate goal of life and happiness is to eat as much as possible.