Since childhood, our parents often taught us that “we need 8 hours of adequate sleep every day” to ensure that the brain rests and relieves fatigue during the day, so that we can have sufficient energy to study, work and live the next day, and our bodies will be healthy and long-lived. Under these influences, many people are convinced that “8 hours of sleep a day” is the right thing to do. If you sleep less, you have to struggle, how to make up for it. Is this concept right or wrong? Nowadays, many people are unable to guarantee 8 hours of sleep, facing the popularity of the second child, the huge pressure of life, fierce competition at work and the temptation of many electronic products, the length of sleep, has been troubling us. In fact, the above statement is both correct and not entirely correct. What is correct is that everyone does need to have a fixed number of hours of sleep (the human body needs three major systems to balance sleep, namely the constant system, the physiological clock, and the waking system). And what is wrong is that the amount of sleep each person needs varies from person to person, just like the amount of meals or food. According to studies, each adult needs an average of about seven and a half hours of sleep per day. However, taking famous historical figures as an example, legend has it that Napoleon only needed 3 to 4 hours of sleep a day, while Einstein needed 9 to 10 hours. Some insomnia patients believe this so much that they even believe that less than 8 hours of sleep a day will produce anxiety. With increased anxiety, the body enters a state of alert, and sleep becomes even more impossible. Secondly, some “deviant” behavior also followed, for example, whether or not to sleep, must let themselves in bed full eight hours, that even if you can not sleep, lying is also the brain and body rest, is beneficial; or, if only six hours of sleep at night, must find a way to make up two hours during the day. In fact, these behaviors may disrupt the constant system of sleep (how much sleep is needed every day, there is a quantitative sleep drive in the body to maintain stability) and the normal operation of the physiological clock. Treating the issue of sleep duration as simply as you would a meal. Everyone has a large or small appetite, and even if you have a large appetite, it is not possible to eat every meal until you are very full. Even if you sleep for 6 hours, when you wake up and feel relaxed and full of emotion, you have achieved the purpose of sleep. Too strict requirements, but indirectly lead to insomnia, so we should always look at sleep with a normal mind.