How much sleep do you need? Have you ever tried to sleep only three hours a day? If so, how do you feel? In fact I never been done it. Before I don't believe people can sleep only 3 hours, it is not enough. Unlikely you sleep less and keep your brain awake. But since I slept six hours recently in order to my new task. Now I couldn't help to say that it is true. If you need cut back on sleep time, you have to force and convince you to concentrate your attention. After I went through this kind of experience which is sleep less. I won't say it is impossible.