One can only go so far inwards. There cannot be "new" material, just the old reworking itself endlessly until it does not resemble reality very much?

I am/was sort of like you, identify with a lot of what you say but have been trapped in my mind before, spent thousands of dollars and hours in therapy to get out.

I think a lot of it has to do with our experiences; if we live mostly in fantasy/our own minds/books, then we don't have any experience with interacting with others. I was relatively sheltered being raised; well educated, etc. but sheltered. The idea of if you only have a hammer, everything looks like a nail comes to mind; if you only have your mind and books you like (do you read books you don't like/agree with?) or grow up only living and working in suburbia, what do you actually know of the larger outside experience? Not much and what is there is kind of boring? Observing is easy, real living and learning to connect with others is much more challenging.