Modern theory holds that dreams are subconscious, and what the brain has not completed is completed by the cerebellum, thinking day and night and dreaming. It may be something I met or thought of recently, it may be Zhang Guan Li Dai, or it may be body double; Perhaps it is a series of books, film and television works, and real-life storylines; It may be because the sleeping posture is not good, a certain part of the body is uncomfortable, and there are similar objects, and related dreams appear. Maybe the dreamer doesn't sleep well and has more thoughts. Maybe I miss, worry, care and prejudice the relatives, friends and people I used to get along with, so I have related dreams. Perhaps it is nostalgia for the past and lost relatives and friends; Maybe it's hope, expectation, fantasy, fear, worry, struggle about what's about to happen ... all of which can't explain anything.