the importance of sleep

sleeping is one of the essential acts for human, and it occupies about one - third of our lives. enough sleep helps people work effeciently, maintain our healths, and keep from sickness. as for the kids, it is quite necessary for their growth. without it, we cannot live. I, sometimes canot sleep until 4 am, even I have to get up at 7 am next morning... when I see the sky gets blight and hear birds began to sing, I feel misery. what do you do when you cannot sleep?