Just ask this question to yourself.
“Is the you right now the real you?”
Maybe you don’t realize this yourself and when your mind is not awake some other consciousness that is inside of you has taken complete control of your body. scary right?
Basically, we all have different personalities inside us. We even wear mask that even the person in question can’t see like for example the “you” that you show to your parents is different from the “you” that you show to your friends. heavy right?
Well, anyway try reading this manga Shi ni Itaru Yamai… this quite a psychological story *emphasis on the psychological* that kind of leaves a bad after taste, a masterpiece non-the-less.