It's an incredibly scary experience that makes you feel like you're disintegrating in a metaphysical sense. Your mind, perception, body. Yourself. Like you're falling apart, being disassembled and that you will never be able to get yourself together again. You have no agency. And then you are gone. I believe this is what they call "ego death".
And then after you're gone, you're left with all these pieces of yourself. Including a lot of them that you forgot ever existed. Or how they fit together. Or some that you were subconsciously aware of but never perceived them. Like opening a shelf of Legos from your childhood. It's very dream-like.
Then comes the awareness, understanding and grief. I've never cried as much in my life, and I'm not a crying person.
Then comes hope.
And you get to assemble yourself back again. Feels like something between waking up, coming back to reality and a chain-reaction of those "AHA!" moments.
And then you're back, but you're not the same, and you understand more about yourself.
While the next few months were some of the best I had in decades, I'm extremely averse to repeating this experience, as it feels really traumatic.
I was in a controlled, safe, although not a clinical environment, and I am terribly aware how much this can fuck your brain up in ways I can probably never imagine. We have no idea how this machine works and this is basically decompiling an incredibly complex binary during execution, moving code around, recompiling, and hoping it works.