Years ago, I spotted an acquaintance I hadn’t seen in a while. The conversation was odd. A few times, I would ask a question and he would begin to respond, only to trail off into silence and stare blankly into space. He would remain frozen until the moment I said something else, whereupon he would act normally. He seemed completely oblivious to the fact that he had trailed off and had never answered my question. Indeed, he didn’t seem to remember that I had asked him a question at all.

These episodes felt interminable — in one instance I waited a good 30 seconds before catching his attention and changing the subject. I wondered for how many minutes he would have remained “paused” if I had never said anything.

I had forgotten this conversation until I came across a passage in our psychiatry textbook describing this exact phenomenon. It is called “thought blocking,” and many patients who have it are schizophrenic. Intrigued, I asked a psychiatry professor about it. He told me that blocking sometimes happens because a hallucination distracts the patient. It also can be because certain impulses in the brain fail to arrive at their proper destinations.

For example, one part of the brain is responsible for keeping the brain focused on certain tasks, like tying a knot to completion or answering a question in a conversation. This part of the brain might have had a faulty neural connection with the regions of the brain responsible for formulating and vocalizing the answer to my question. It’s fascinating.

Currently in anatomy class, we are dissecting the brain. It is not a particularly large organ (perhaps it’s the size of a cantaloupe), nor is it terribly heavy (about three pounds). Yet it contains everything that makes us human. This pink blob is not only what makes us see and breathe, but also what underlies envy and love, music and literature, war and civilization. Discovering new things about the brain makes it all the more inscrutable: how is it that two almond-sized regions of the brain contain our most visceral emotions and fears? It’s baffling. One of my textbooks points out that the number of neuron cells in one’s brain approximates the number of stars in the Milky Way.

Wonderment at the splendor of the human brain goes back as far as Plato. Yet today, not only do we understand much more about the human brain, but the rate at which we are unlocking the mysteries of the mind continues to accelerate.

I often dwell on the sacrifices that medical school entails — financial, social, personal, relational, and emotional. But, we get to study the brain. We even get to marvel at it by picking it up and holding it in our own hands. It reminds me yet again that this enterprise of becoming a physician is a rare privilege.

“Reflex Hammer” is a medical student who blogs at The Reflex Hammer.