"The ass is another animal who is celebrated as the greatest fool, even amongst the animals. The ass works very hard and carries burdens of the maximum weight without making profit for itself. Footnote: Human life is meant for earning values. This life is called arthadam, or that which can deliver values. And what is the greatest value of life? It is returning home, back to Godhead, as indicated in the Bhagavad-gita (8.15). One's selfishness must be aimed at the point of going back to Godhead. The ass does not know its self-interest, and it works very hard for others only. Similarly, a person who works very hard for others only, forgetting his personal interest available in the human form of life, is compared to the ass. In the Brahma-vaivarta Purana it is said:

So asitim means eighty. Asitim caturah. Caturah means four. So eighty-four. Eighty plus four means eighty-four. Laksams. Laksams means hundreds of thousand. So eighty-four hundreds of thousands. Asitim caturas caiva laksams tan jiva-jatisu. Jiva-jati. This is different species of living entities. Jiva-jati. The hog species, the ass species, the dog species, just like they have got species. Jiva-jatisu. So in different species of living entities, they are counted, eighty-four hundreds of thousands, or 8,400,000. Bhramadbhih. Bhramadbhih means transmigrating, wandering one after another. Jalaja nava-laksani sthavara laksa-vimsati. There are 900,000 species within the water.

Then trees, plants. In this way, passing through different species of life, the living entity… Jiva-jatisu. Jiva-jatisu, in different species of life, he is transmigrating, one after another, one after another. Bhramadbhih purusaih. Purusa. Purusa means the living entity. The living entity is described here "purusa" because he wants to enjoy. Purusa is the enjoyer. Actually enjoyer is Krsna, but we are imitating Krsna. We want to become God. That is the Mayavada philosophy. That is our trouble. I am trying to imitate something which I cannot. Suppose if I want to be God, is it possible to become God? But they are trying to be. Bhramadbhih purusaih. So in this way, for this misunderstanding, he is falsely trying to have happiness through so many species of life. "Let me enter this life, let me enter that life, that life, that life, that …" In this way he falls down. He is fallen already from Vaikuntha planet. He is fallen in this material world, and he is again trying to make progress" - Srila Prabhupada, Srimad-Bhagavatam 2.3.19, Los Angeles, June 15, 1972

One’s selfishness must be aimed at the point of going back to Godhead