The Professor Was Wrong. My Gut Knew It the Moment He Said It.
In 1973, the human cadaver pro-section lab at Stanford University was housed in a small one-story building off to the side of the main campus. One of the few structures that had survived the 1906 San Francisco earthquake. You walked in and the smell hit you — formaldehyde, thick and immediate. That smell meant you were somewhere serious.
I was there as a graduate student in the anatomy and physiology program, studying alongside first-year medical students. We had lectures from two physicians who had come over from South Africa — rigorous, old-school, the kind of academics who treated anatomy as something close to sacred. Dr. Milan was the older of the two. Deeply knowledgeable, professorial in his manner. Not a man who invited casual disagreement.
One afternoon we were working through the cranial nerves. There are twelve of them, numbered by position. When Dr. Milan reached number ten, he said something that stopped me.
The vagus nerve, he told us, was now considered to be nothing more than a vestigial structure. A remnant. No remaining purpose in the body.
I sat there and thought: that can't be right.
I didn't have data to argue with him. I was a graduate student. But I had basic logic, and the logic didn't hold.
The body evolves under enormous energy constraints. Anything that costs metabolic resources and serves no function gets eliminated over time — not over decades, but across millions of years of deep evolutionary pressure. That's not a controversial claim, it's just how evolution works. And the vagus nerve is not a small, vestigial stub like an appendix. It comes out of the brainstem and travels the full length of the body, branching into virtually every major organ system along the way. You don't maintain something that anatomically elaborate for fifty million years if it does nothing.
I noted Dr. Milan's contempt for it. Kept my mouth shut. Filed the question away.
That was 1973. It took years for the answer to come. But it came.
The vagus nerve is now understood to be one of the most important structures in human physiology — the primary highway of the parasympathetic nervous system, the one responsible for rest, recovery, digestion, and regulation. It connects the brainstem to the heart, the lungs, the gut, the immune system. When researchers talk about the gut-brain axis, the two-way communication between your digestive system and your brain, the vagus nerve is the main channel that carries the signal.
Vagal nerve stimulators — surgically implanted devices — are now FDA-approved for treating epilepsy and depression. Clinical trials are underway for rheumatoid arthritis, Crohn's disease, PTSD. Heart rate variability, one of the best markers we have for stress resilience and cardiovascular health, is largely governed by vagal tone.
Dr. Milan wasn't slightly off. He was spectacularly wrong. The nerve he dismissed as evolutionary dead weight has become one of the most actively researched structures in modern neuroscience.
I've thought about that afternoon a lot over the years — not because of the vagus nerve specifically, but because of what it gave me.
A method.
When an expert dismisses something in a way that doesn't hold up to basic logical scrutiny, pay attention. Don't argue — you probably don't have the standing to argue, and argument isn't really the point anyway. Just note the dismissal. File the question. Then go find out for yourself.
I've been doing this my whole adult life. It's the same posture that led me to the circadian biology research before most people had heard the term, to the gut microbiome work years before it went mainstream. To the heat protocols, the red light therapy, the cold exposure research. In each case, the early signals were there long before the consensus caught up. And in each case, someone credentialed was waving the question away.
What I'm skeptical of is the false certainty that sometimes travels under science's name — the confident dismissal of things we don't yet understand, dressed up as expertise.
The vagus nerve in that earthquake-era building taught me to watch for that.
These days, I spend part of every morning deliberately activating it.
The pelvic contractions. The leg shuddering. The humming, the sighing, the breath work. All of it is vagal activation — techniques drawn from somatic therapy, breath research, and the neuroscience of the parasympathetic nervous system. Before I've looked at a screen, before breakfast, I spend time waking up the nerve that Dr. Milan told me had no purpose.
It's become the foundation of everything else. The thermal protocols work better when the vagus is primed. The gut responds better. Sleep is more regulated.
I knew it mattered in 1973. In a building that smelled like formaldehyde. Because the logic said so, and I trusted the logic over the authority.
That habit — holding a question open when the official answer doesn't make sense — may be the most useful thing I've ever developed. It's not always comfortable. Experts don't love it when you do this. But it pays.
Fifty years of held questions have produced a morning protocol — and a way of thinking about the body — that I'll keep laying out in this space. Next up: what your body actually runs on, and why the first thirty minutes after sunrise may be the most important biological window of your day. It's the kind of thing Dr. Milan would have dismissed in 1973. The research now says otherwise.
If you want to follow that thread, subscribe below. Twice a week. Free. Everything I write comes from the same posture I described above: the thing didn't make sense, so I went and found out.
I'm not a physician and nothing here is medical advice. This is a personal record of what I've tried, measured, and found. Run anything you want to try past your own doctor first.
Tom O'Connor is the founder of 75goingon50.com. He lives along Hood Canal in Washington State.
