I'm sure the story was inspired by hallucinogenics but not penned or sketched out whilst under the influence. Like you said it can be your only objective not to fall off the planet whilst on mushrooms. It's the secondary effects days later where the mind is open to all sorts of suggestions that just seem to come from another world. Maybe lsd and the likes are just a natural technology to blast us into the dreams of our fellow earthlings, who knows? Really great post!