"Is this…enlightenment?" I asked.

"We use the word 'Awakening'," said the Zen Master, kindly.

"Now what?" I asked, "Every book I've read about meditation is about getting to this point. There's nothing about how to safely navigate the territory afterward—or what to do afterward—or even what happens afterward."

"The first thing you need to know is that what you experienced was real," the Zen Master spoke from personal experience and that of his many previous students, "Don't make it too complicated. Just be in the moment. If you're cooking, then just cook. If you're eating, then just eat."

It is impossible to communicate the subjective experience of Stream Entry to someone who has not personally experienced at least kensho. However, it is possible to communicate an outside mechanistic model of what happens in your brain. First I will explain how a human brain functions normally. Then I will explain how a post-Awakening brain differs.^[1]

Your brain creates a real-time simulation of you and world around you. Everything you consciously perceive is part of this model. There are no exceptions. How does this produce useful behavior? Because the brain enforces a 1-to-1 correspondence between the simulation and reality (where "reality" is defined as sensory inputs). If this 1-to-1 correspondence is adequately maintained, then performing an act in the simulation happens simultaneously as that same action happening in external physical reality. That's why if you die in the Matrix then you die in real life too.

If a brain just modeled the environment without performing any actions, then the whole model could exist as a non-cyclic graph. But a brain doesn't just model the world. It sends commands to muscles that act on the physical universe it's trying to model. What happens when a brain tries to anticipate its own motor commands? Now the brain's own algorithms are a causal force in the external environment it's trying to model. The result is computationally intractable.

In response, the brain divides its model of the universe into "things under its motor control" and "things not under its motor control". Those parts of the universe it can control coalesce into "self" and the rest coalesces into "other".

Other calculations involving self-reference become encapsulated too. This produces high-level abstractions including pain, pleasure and desire. These encapsulations feel like part of the self, because they involve self-reference, but they also feel like objective external truth, because they are not perceived as being under causal motor control.

There are many types of meditation^[2], but most of them involve sitting still and all of them involve not taking self-motivated willful action on the external physical world. In other words, meditation is when you stop doing things that cause problematic self-reference in your world model.

When you do this, all of those abstractions created to contain problematic self-reference become unnecessary. Desire, pain, pleasure, self and other—they all no longer serve a purpose. Stop using them long enough, and your brain takes them apart, like disassembling a Lego set.

When you start meditating and sit in the full lotus position, your legs fall asleep and you feel a pain in them. After you've been meditating for years and sit in the full lotus position, your legs fall asleep and you feel the vibratory sensory inputs directly, without the encapsulation layer called "pain". The concept of "pain" is no longer a meaningful abstraction in your world model. Talking about pain to a yogi is like talking about "God" to an ex-Mormon.

Lots of models get dissolved. Prior to meditating, I felt like I was a small person walking around a region of Cartesian Space containing Planet Earth. Now I feel like a local region of local space is being created and destroyed around me like how the Minecraft game engine loads and unloads blocks. This happened because I got a direct enough perception of my own conscious reality that an illusion shattered and my perception shifted permanently. It was like going out-of-bounds in a videogame speedrun. You can never unsee the behind-the-curtain mechanics of how that reality is constructed.

But what really surprised me is what happened over a year later.

I'm autistic. Most of my life I've had trouble understanding other people and guessing how they want me to behave. In my late teens/early 20s, I studied history, anthropology, psychology and economics. This helped a bit.

Then a couple years ago I hit Stream Entry (aka Awakening) when I observed a bunch of my own mental processes that had been hidden from me. The internal workings of these parts of my mind had formerly been encapsulated away from my self-perception. But now I saw what they were doing. That reduced my subjective experience of suffering.

It also allowed me to infer these same processes in other people. Suddenly other people weren't confusing anymore! I could predict how someone's ego would react to the things I said before I said them.

This was useful because I could finally conduct probing psychological experiments on my friends. I had always wanted to know what people were thinking, but whenever I tried to ask, people would get hurt and defensive. Now I knew how to not trigger those defense mechanisms. That meant I could run a series of experiments where I sat my good friends down and tested how their minds worked. Not only did they not feel attacked, they usually felt that they'd been deeply heard, as if they'd been to a therapist. I could call a friend an idiot to his face and he'd shrug and go "yeah".

That solved one problem, but I still had my original autistic sensory disorder. Meditation was making it worse. Meditation makes you extra sensitive to sensory stimuli. Autism (I think) is caused by your sensory inputs having too much gain, in the audio signal-processing sense of the word "gain".

This continued for months. I bought the most comfortable clothes I could find. I installed blackout blinds over my windows. I bought a pair of Bose noise-cancelling headphones and wore them everywhere. I wore them so much I wore them out and bought a second pair. I wore earplugs to ballroom salsa dance.

Then the wave crested. A friend invited me to his birthday party with loud music where we played my first game of beer pong. I had to take a breather outside once or twice from the noise and chaos. But I felt…normal…for the first time in my life. I knew what the social expectations were and I followed them. This was different from my previous attempts to behave like a normal human being because I wasn't doing it on a cognitive level. It was just intuitive. My autistic sensory disorder was no longer overwhelming my social intuition instincts.

Since then, my sensory issues have gone into in freefall. I think I've had a successful round of meditation-instigated neural annealing. I went to a bar for New Year and didn't have any sensory issues at all. You know that stuff Dale Carnegie teaches about listening to people? It's easy after ego-death. I was told I had good vibes. Someone tried to buy me a beer. I lost track of how many people hugged me just because I had listened to them.

I felt like a Bene Gesserit trainee.