Sleeping means just like when we sleep, we forget ourself. Anyone, either common man or a very rich man, when he's fast asleep he forgets himself. Sometimes he dreams. Although he is sleeping in very nice apartment, nice bedstead, but he is dreaming that he is thrown into the ocean or into the fire or something like that. Sometimes he is dreaming that he is flying in the sky—so many things dreaming. Everyone, you have got experience.
Similarly, our this state of consciousness, material consciousness, is on the sleeping state, in the darkness of sleeping state. We do not know. We do not know what is my identity. We do not know wherefrom we have come in this place, where we have to go. Neither they have any information whether there is life after death. Very gross understanding, just like animals.
Animal is standing, eating some grass. Although next moment he'll be taken to the slaughterhouse and he'll be killed, but he has no information. He is very happy eating the grass. And even if it is informed, "My dear Mr. Ox, you are eating grass here very happily. Just half an hour after, you will be taken to the slaughterhouse. You go away from this place," but he has no knowledge. This grass-eating is very palatable to him than to take protection from being killed.
So this is called ignorance, ignorance, sleeping state. Therefore the Veda is crying, uttiṣṭham jāgrata prāpya varān nibodhatam, kṣurasya dhārā niśitā duratyayā (Kaṭha Upaniṣad 1.3.14). "You have got now this human form of life, a great boon, not like animals. Please do not therefore waste your time sleeping like animals simply in the matters of eating, sleeping, mating and defending." That is the verdict of Vedas. Vedaiś ca sarvair aham eva vedyaḥ (BG 15.15).
Therefore, human life should be very much responsible. This life is the preparation for the next life. Next life we have always, but we do not know what kind of life we are getting next. That we should know. That is the business of human form of life, not to waste life like animals and evolve. By the laws of nature, we get another form of life.