I have an expression- well, I'm sure I didn't coin it- it's probably in Hubbardite stuff somewhere- but anyway, a person can get "interiorized into the game". I think Hubbard did so. I think there're degrees of that and if a person does it to a very strong degree, they go nuts. It does appear that he became quite irrational.
Yes. It could also be called "not seeing the forrest for the trees."
We all have to step back and look at the "Big Picture" as best as we can from time to time. Then we can get back into the "the game" (or the forrest) if we choose, or move on to another game or forrest or beach or mountain or city or ........