When you're dreaming a surreal dream and you cannot tell the difference between your dream and reality, they tell you to look for something that is out of place.
Something that is missing.
When you look up at the dark sky and you wonder to yourself, "where are the stars?" When you stop and ask yourself, "where is the quite hum of the night?"
When something is missing, that is when you know you're asleep and dreaming.
But what happens when you wake up and realize that you are missing something from this reality and only in your dreams do you feel like you are whole and all the pieces fit.
Then do you choose to sleep forever or walk this life always looking for the missing piece, not even knowing what you're missing or who?