Is creating a separate reality with your mind possible?
Occult esoteric shows like Invader Zim had the character Dib create a separate reality full of evil creatures using only his mind, and Adventure Time's Ice King had a gender reversed version of reality existing inside his own mind.
I feel like there must be some truth to this. In the Invader Zim episode, I even remember the evil creatures using Dib's head as a portal to the human world.
https://www.wcoforever.net/invader-zim-episode-25-halloween-spectacular-of-spooky-doom
(watch in a download browser to download the full episode and avoid monetary interruptions)