The  Srimad-Bhagavatam  says that most people do not know their self-interest in life. It is like coming to a crossroads and not knowing the way. Suppose you are going to Philadelphia, and after crossing New York City, you see a crossroads, and you do not know the road. Of course, in America, there is a very efficient system of direction on the roads. That way, you have no misguidance. Similarly, in the scriptures the Vedic literature gives you direction. Yes, here is a crossing. If you want to go this way, you may. So the  Bhagavatam  says that people do not know the direction by which to make progress. One must know that he must make further progress toward Visnu. Why? Because this is a very highly developed life. In this form of life, we have very high intelligence. We have more intelligence than cats and dogs and other animals. Why misdirect it? The misdirection is due to being attracted to this bodily concept of life. One is thinking, “I shall be happy utilizing the body and the senses to the utmost.”
Because we do not know what our progressive life is, we are trying to squeeze the essence out of this body. To enjoy it. In the  Bhagavatam  there is a very good example cited about these foolish men. They are compared to the camel. The camel is a desert animal very fond of twigs containing thorns. They have very long necks, and they take a bunch of twigs with thorns and begin to chew. By contact with the thorns, blood oozes out the tongue. Naturally, if you chew thorns, your tongue will be cut. So, when they take those thorns within the mouth and begin to chew, the blood comes out. And when the blood is mixed up in that form, they eat it, because blood has a taste he likes. He thinks that twigs with thorns are very tasteful. Our sex life is like that. Just squeeze it out of the body, and we think we are enjoying it. This is our position.
Another example is given. In India the washermen keep asss. They load the ass as much as possible. The ass works all day and in the evening, he is offered some grass, and he's satisfied. For a morsel of grass, he is ready to work the whole day with half ton of clothing on his back. Similarly, we also, the  karmins , are very busy working all day and all night. And when we come home, we eat only one piece of bread. For one piece of bread, which costs no more than ten cents, one is working all day and all night. So the comparison is to the ass. The ass does not know for whom he is working so hard, and taking some bread. “This is the aim of my life.” Is it my aim of life—to eat something and go to sleep, and have some sex pleasure and then die? No, this is not the aim of life. Your aim of life should be to realize yourself—that you are part and parcel of the Supreme Absolute Personality of Godhead, Sri Krsna. Krsna is awaiting your arrival, so that you can enjoy life in His association.