Some people say that dreaming is because the brain is not rested, which will affect sleep and health; others say that it may be the side effects of certain drugs. In fact, it is not, dreaming is a phenomenon when people sleep, is a very common thing, everyone is dreaming, it can be said that no one does not dream. In the past, science is not developed enough to explain the phenomenon of some things, the dream is said to be a variety of different, adding a confusing, magical and mysterious, the color of the gods. ”This is a simple materialistic explanation of dreams, which is of great practical significance. Most people have this experience. If you think about something during the day, you can dream about it at night. Recent scientific research has shown that dreams are actually some “traces” of activity in the cortical cells of the human brain left by some stimuli in the environment. Some people think that dreaming is good for you to solve your problems. For example, Nobel Laureate Otto Loy, a German, had a dream when he was in trouble at work. When he woke up in the middle of the night, he immediately wrote down a very strange idea of solving the problem in his dream, which later proved to be correct. People think of dreams as disturbed sleep, and do not see them as good sleep. In fact dreaming can play a role in protecting sleep and dreaming helps mental balance. According to Freud: dreaming helps the creative function.