What Do You Do?

Have you ever go somewhere late in the night and come back home in the morning? I still can't understand completely about this. Why some people can stay awake until morning to do something which is not so important at all. They said it's for relaxing and having fun. But what is the point? Because the next day, you will so tired and you will sleep the whole day to replace your sleeping time that you miss during the night then you will wake up in the afternoon when the sun will start to go again. What will happen? You will mix up your sleeping pattern. And I am sure it will not be so easy to turn back your sleeping pattern again into a normal one.