For example: if you study physics, a mountain (which you consider real) is discovered to be mostly made up of empty space, and the rest of it made up of probabilities. Then, later you find out how this almost nothingness actually forms a solid object.
I agree, and I find the dynamic interesting as knowing being about information and patterns. It's like the Knowing, Understanding, Wisdom triad in Cabalistic philosophy. The first is contact with what is being known. The second is embodiment and ownership of the information, and the third is being able to apply it.
In the case of the Zen phrase, the senses give you the mountain. Meditating makes it disappear because you internalize. Then the reality of the senses and that of the meditation merges, and it all just is. That's a bit similar to the triad Knowledge, Understanding, Wisdom- names of sacred centers on the Tree of Life.
As one who spent years undergoing psychedelic journies for transformation purposes, the folks that just trash that path are wrong. I can testify to that. However, they are also statistically correct. That means most humans are better off not touching that path unless they are well-prepared psychologically, not beginners in esoteric exploration, and very careful regarding who is with them, and where they do it and why (the real why).
What I did was an orchestration with art, nature and technology to create the right environment. There is something I read somewhere that I observed: people with a deep and unaddressed shadow if doing stuff with people of a deeper consciousness can under high doses end up trading places with their shadow persona. They tend to undergo an identity crisis, after which they emerge as an archetype form of their own shadow.
The quote I had read, or maybe a study, claimed that one will either come out of a trip as one's better self, or fall into a narcissistic or psychopathic mental hamster wheel that can be like possession. Or in some cases, the real nasty persona some folks have...comes out but with a more dramatic status than just a petty human nastiness.
So nobody just turns on an automobile without having a clue about driving other than turning the car on and getting it moving...fast, unless they are wanting to risk a crash. Sticking unpredictable substances in the body can also make one crash, even when the substances are safe, but the atmosphere that opens into one's perception on these substances may not be.
The perception opening up is just that. It isn't just made up. And one can end up drawing the attention of some of what is "out there". Interestingly, after a few years of people leaving this group and only the stable diehards remaining to push the envelope, a friend of mine got seduced by a girl that was sent by some Kali temple in California by the High priestess to check out a certain psychic irregularity that she traced to us.
Then she tried to poison my friend after seducing him....So, yeah,....caution is a good thing.