something something. dont they have those quantum theories?
In the quantum theory called the Many-Worlds Interpretation, every possible outcome exists in different branches of reality.
So when you dream something horrible and wake up relieved, it almost feels like your brain briefly experienced a different possible branch - then snapped back to the one where everything was okay.
Not actual proven physics of course… yet…
Its a fun way to think of it, but more likely it is your unconscious modeling worst-case outcomes.