I spent months underwater on a US submarine and felt the same thing. Later the Navy pdoc labelled it dissociation, which is in the DSM.
Common Types and Symptoms
Depersonalization: Feeling detached from your own body, mind, or actions, like watching yourself in a movie.
Derealization: Feeling that the outside world is fake, dreamlike, or foggy.
Dissociative Amnesia: Forgetting important personal information or blocks of time that go beyond normal memory loss.
Identity Confusion or Alteration: Feeling unsure of who you are or experiencing shifts in your personality.
Causes and Triggers
Trauma and Stress: Acts as a defense mechanism against overwhelming stress, abuse, or frightening events.
Everyday Triggers: Loud noises, strong emotions, or reminders of past trauma.
Mild States: Getting lost in a book, daydreaming, or "highway hypnosis" while driving.
