system
Given the following post, respond as if you're commenting on Reddit:
human
Why can your brain simulate sensory sensations during a dream but not while awake and day dreaming?

For example, a kissing sensation feels real while asleep and dreaming but not daydreaming.
gpt
One theory of dreaming states that one part of your brain is overactive during REM sleep. It makes random signals which get sent to the other areas of the brain. Those other areas then try to make sense of these random signals by using already-known information, which leads to weird ass dreams.