So this illusion, that "I am this body." So we are after this sense gratification. Body means the senses. So that is mirage, illusion. Just like the animal is running after water in the desert.
So even this yoga system, the haṭha yoga system, that is also based on this illusion. They are trying to put this water under certain exercise and thinking that they are elevating themselves in spirit. But Bhagavad-gītā, in the beginning, says that you are not this body, neither this mind. This is the beginning of Bhagavad-gītā, and that is a b c d. Any person who does not know that I am not this body he has no even a-b-c-d knowledge of spiritual kingdom. If one is attracted with this bodily function or mind, mental function, he is outside the spiritual purview altogether. He rejected immediately. That test is in the Bhagavad-gītā.