Then wake up yourself. First of all, when you are in good health, it is ok to get insufficient sleep occasionally. Don't always do this. If you don't get enough sleep, your body can't eat, and if you are overworked, you will get sick, both physically and physically. The alarm clock is still low, just put it under the pillow, and the vibration of the mobile phone will wake you up. There is another best way. I have tried several times and the success rate is very high. For example, if you want to get up at six o'clock in the morning, you have to dig your forehead before going to bed and tell yourself that I get up at six o'clock in the morning, get up at six o'clock in the morning, and knock on my forehead several times when I get up and repeat it three times. But if you are too sleepy, it is definitely not possible. It means you go to bed at nine and get up at six the next morning. You don't have to set an alarm clock to hit your head and tell yourself to wake up before 6 o'clock.