Dreaming and waking up and forgetting is related to the depth of sleep, which is a normal physiological phenomenon. Normal human sleep includes two processes: rapid eye movement sleep and non-rapid eye movement sleep. The first is the light sleep of non-REM sleep, and then the deep sleep of REM sleep, during which dreams are possible at any time. If you dream during the REM sleep stage, you will have a memory of the dream when you are awake at this time; if you dream during non-REM sleep, it is not easy to recall the dream when you are awake at this time. In addition, changes in the sleep environment and psychological factors can affect the depth of sleep. If there are problems such as anxiety and nervousness, it is recommended to consult a doctor at the hospital.