There is a line from the Māṇḍukya Kārikā that I often carry with me into the operating room—not as philosophy, but as a quiet warning:

“अविद्यायां न हि विद्याम् अविद्याम् वेत्ति मानवः।”
The one immersed in ignorance knows neither knowledge, nor that he is ignorant.

The Māṇḍukya Kārikā presents a succinct, verse-form exposition of the Mandukya Upanishad—one of the shortest yet most profound Upanishads, comprising only twelve statements. Centuries later, psychologists David Dunning and Justin Kruger described the same human tendency in scientific terms:
those with the least competence often overestimate their abilities.

Neurosurgery, with its unpredictability and unforgiving precision, is a perfect stage where this illusion of knowledge can collapse—sometimes gently, sometimes abruptly, and sometimes dangerously. Over the years, I have seen it surface in patients, families, trainees, colleagues, and occasionally within myself.

For readers who have followed my earlier reflections on uncertainty in neurosurgery 🔗, this theme will feel familiar. For those encountering my writing for the first time, this essay stands on its own—as an attempt to describe how confidence, when detached from awareness, quietly becomes risk.

---

A few weeks ago, an old school friend called me from a metro city. His voice was calm, almost reassuring—the way it sounds when a crisis has already been mentally downgraded.

“Papa had a small stroke,” he said. “Nothing major. Facial droop, a little garbled speech. We showed him to the best doctor near our hometown.”

His parents live in a smaller town near our native place. Close enough to reach quickly. Far enough for layers of expertise to thin out without anyone quite noticing.

The local doctor did what any sincere, ethical physician would do. An MRI was ordered. The scan was performed on an old refurbished machine—functional, but limited. Thick slices. Suboptimal resolution. The local radiologist read the scan and issued a detailed report, commenting confidently on multiple findings—many of which are inherently difficult to interpret with that level of image quality.

Medicines were prescribed. The symptoms improved. He was sent home.

By the time my friend called me, reassurance had already settled in.

“Doctor said MRI is fine. Papa is okay now.”

When he forwarded the images to me, what unsettled me wasn’t an obvious abnormality. It was the false sense of completeness. The scan simply could not answer the clinical question definitively. The radiologist, to his credit, had tried to be thorough—but thoroughness built on weak data often creates an illusion of certainty.

No one here was negligent.
No one unethical.
No one careless.

Yet ignorance quietly compounded itself at multiple levels.

The radiologist reported beyond what the scan could reliably show.
The physician, busy and well-meaning, relied on the report.
The system rewarded closure over doubt.

No vascular imaging.
No etiological work-up.
No discussion about preventing the next stroke—the one that might not be minor.

The patient went home reassured.
The family felt relieved.

अज्ञानात आनंद. (Bliss in ignorance)

This is the Dunning–Kruger effect in its most realistic form—not arrogance, but confidence born from incomplete awareness. You don’t know what you don’t know. And when you don’t know that you don’t know, certainty comes easily.

---

I have seen the same pattern repeat itself in clinics.

A patient once arrived with a referral note written in a confident hand:
“Cervical radiculopathy. Conservative treatment advised.”

He was comfortable. Calm. The diagnosis had been delivered with assurance. When we reviewed the MRI together, an intradural tumor at C2–C3 quietly declared itself—compressing the cord just enough to matter.

The referring physician wasn’t careless. He had simply stopped questioning once a plausible answer appeared.

In medicine, knowing a term is not knowing the terrain.

This is something I have reflected on earlier while writing about clinical decision-making in neurosurgery 🔗—how labels can prematurely end curiosity, and how neurosurgical pathology has little tolerance for that closure.

---

The illusion of knowing has become louder in the digital age.

Patients now arrive fluent in terminology—hydrocephalus, disc bulge, stenosis—often explaining to me how water intake, posture correction, or a particular exercise regimen will “reverse” structural disease. They have read. They have watched. They are informed.

But information is not understanding.

The Dunning–Kruger curve thrives where access to data masquerades as depth. Neurosurgery teaches a harsher truth: knowing a diagnosis is not knowing its behavior. Knowing a word is not knowing its weight.

---

I see this most honestly during training.

A junior resident once watched a microdiscectomy and remarked, sincerely,
“Sir, this looks very straightforward.”

The following week, during supervised hands-on training, a small dural tear transformed a similar case into a lesson no lecture could deliver. The surgery remained controlled. The outcome was good. But something important had been punctured.

Complications are nature’s way of puncturing the illusion of expertise.

I have written before about how complications in neurosurgery 🔗 are rarely just technical events. They expose cognitive gaps as much as anatomical ones.

To the beginner, surgery appears linear.
To the experienced surgeon, it appears fragile.

The more you truly know, the quieter you become.
The less you know, the louder you may speak.

---

Sometimes, the illusion does not originate with clinicians at all.

I once encountered a well-intentioned administrative plan by a corporate hospital CEO to schedule complex craniotomies back-to-back in the name of efficiency. On paper, it was elegant. In reality, it ignored fatigue, ICU logistics, neuromonitoring availability, and postoperative unpredictability.

Confidence built on partial visibility is still overconfidence.

Healthcare systems, like individuals, suffer most not from ignorance—but from unrecognized ignorance.

---

Across all these stories—the minor stroke sent home, the missed spinal tumor, the confident trainee, the informed patient—the pattern remains unchanged.

The Dunning–Kruger effect is not a psychological curiosity. It is a daily clinical reality.

Those who know the least often sound the most certain.
Those who know the most choose their words carefully.

Neurosurgery enforces this lesson relentlessly. The brain does not tolerate arrogance. It exposes assumptions without malice.

And perhaps that is the enduring lesson—echoing from the Māṇḍūkya Kārikā to modern psychology:

The most dangerous moment in medicine is not when we admit uncertainty.
It is when we believe we already know enough.

–Notes on the Dunning–Kruger Effect from the Inside of Neurosurgery

Dr. Nitin Jagdhane
Your Trusted Neurosurgeon