Dreams are good and bad. Many people use the usual secular concept to distinguish, dreaming of promotion and wealth is a "good dream", while beating, killing or dreaming of beasts, dead people and devils is a "nightmare". There are many popular "dream interpretation" books in society, including The Duke of Zhou in ancient China and the theory of "dream interpretation" by foreigners. Interestingly, according to the dream book, those who dream of getting rich are not "good dreams", but fighting and killing people are "very good" ... these can only be used as food to satisfy their cravings, but they can't be true!
According to Freud's theory, the human brain has two regions: the conscious region and the subconscious region. People should focus on their immediate work and life during the day, so they put all the information accumulated many years ago into the subconscious field. It seems that there are full-time brain cells on duty. So that when we usually go to work or study at school, most of us only pay attention to what happened in front of us, but temporarily forget what happened many years ago and bury it in our minds. But when I fall asleep at night, the excitement turns to inhibition, and even the brain cells on duty are in a "rest" state, so everything that was originally suppressed in the subconscious field runs out. That's why I always dream of my childhood or my grandparents who have died for many years ... My son is thirty years old, but the son I see in my dream is always a child who will never grow up and wants me to take him out to play! These circumstances are enough to prove that I slept soundly and got a rest that night.
On the contrary, if you dream at night that what you did during the day is still going on, or that the person in your dream is the person you contacted recently ... it means that the nerves working during the day have not been rested, and they are still working at night, and the cells on duty responsible for suppressing the escape of past information seem to be difficult to remain loyal to their duties in the "night shift"! So it proves that I didn't have a good rest this night.
As for the inverted image in the dream, the reasons are also very complicated, and most of them involve the "take it" of the nerves. Practice has proved that people who often "dream" will feel very tired, which means it is not a good thing.
Some people think that "dreaming" is to throw away some "rubbish" in memory. This statement is very novel. Whether there is a scientific basis needs to be studied.
I like studying dreams. I have found that those who dream that they can "fly" can jump several feet, have endless abilities and defeat powerful enemies ... most of them are in good health. Once you are always unable to walk, run fast, and have no strength, and you are afraid of this and that in your dreams, it is time for weakness and qi deficiency. As for sleeping, I always want to eat in my dreams because my stomach is empty. When I am in a hurry, I always look for a toilet in my dreams, or I always swim around in the water, and so on. It is a normal reflection from physiology to psychology.
Don't travel frequently, don't often change unfamiliar beds, don't always stay awake and sleep on duty ... it's not easy to sleep without a fixed place and fear. Of course, the person who can't sleep well is a hypocrite with a guilty conscience. This kind of person who sleeps every night is equal to suffering and deserves it!