As the saying goes: think about it day and night. Some, but not all.
1, the formation of dreams. 2. The difference between dream and reality.
When you wake up from sleep, the dream is formed. There is a difference between dream and reality.
Because it is formed when you wake up from sleep. Some can remember, some are vague, some are subconscious, so. The dream is not clear. Metaphorically, dreams are like messy tapes. When playing, some are clear, some are unclear and some are silent.
At present, there are many schools in the study of dreams. Opinions vary.