I cannot word it coherently but I will try! Succinctly it feels like the scene in The wizard of Oz where Dorothy see that the Wizard himself is nothing more than an ordinary man behind a curtain.
I started an intense spirutal quest after a meditation session¹, that unexpectedly left me disoriented, depressed and generally dysfunctional. My first few trips after that event made me hopeful again but left me curious as I felt that there was a deeper truth to be found.
1-in a college course on meditation (I had the choice between soccer, golf and meditation... in retrospective I should have chosen Golf)
At that time most of the more obscure hallucinogen described in Tikal and Phikal were legal and easy to obtain from Sigma-Aldrich at reasonable price and I knew people who could obtain quality LSD. So I tried almost everything that Shuglin described as +++.
But it's repeated combination of dextromethorphan (a surprisingly complex drug that is mostly a dissociative) and things in Thikal (LSD, 4-AcO-DMT, 5-meo-mipt...) that pulled on the curtain. 350mg of DXM made me prone to recursive toughts without blocking my ability to remember and the tryptamine brought the spiritual aspect. After thinking about thinking that I am thinking for what felt like a thousand years I came to experience the holodeck effect where you can will any scene into "existence", it's my repeated interactions with my "holodeck" that pulled that metaphorical curtain to reveal that the Wizard was nothing more than a physical process inside me.
After that I lost my access to the holodeck, hallucinogens became physically unpleasant and mentally uninteresting. My quest ended as I felt that I had learned what could be learned about spirituality and stopped worrying about a deeper hidden meaning in life. Things happen because they happen and there is no answer to why something instead of nothing (a complete nothingnes, not the nothingnes of a perfect vaccuum) and it doesn't matter!