Sometimes when I’m working at the hospital overnight, I go for walks. Every now and then, things calm down in the operating room, and you can get some time to relax. Life moves at such a break-neck pace, especially within the world of hospitals, that taking a moment to reflect, is beneficial.

Walking around a hospital at night is very different than during the day. During the day, it feels like a corporation with suited men and women roaming from meeting to meeting, it feels like train station, where buses and cars move in and out of lots. It sometimes feels like a factory where patients come for the acute care that only a hospital can provide.

But at night?

At night, hospitals take on a whole different feel. When I walk around, there are few people moving about, but each one is moving with a purpose.

A resident physician on no sleep fumbling with notebooks filled with endless pages of diagnoses and treatments for the 20 patients on their service.

A man pushing his IV pole down the hall, convincing himself that just one more step will help him get better and out of here.

A nurse, having just come to work at midnight, eating “lunch” and discussing with her colleagues what it’s like to live a life directly inverted from the lives of other people.

I’m listening more carefully at night as I stroll through the darkened halls. The walls echo a variety of emotions, each distinct with vigor and substance.

“I just don’t want to watch him suffer,” a middle-aged man says to his mom, just outside of his dad’s room.

“It has feet!” says the man looking at his newborn daughter’s body just after his wife’s delivery.

There is art on the walls.

Lining up the walls of a hospital near you is artwork from distinguished artists around the world. I read the descriptions, the artists’ names and feel a sense of gloom. I don’t usually notice the art because the truth is, no matter how hard you try to make the hospital a more pleasant place, it most often will remain cold.

It is filled with caregivers, whose sole purpose in their professional live, is to take care of the sick. And with all that love and devotion, their empathy can only extend to the hand of those reaching. Sometimes, you can reach their hearts, and when you do, you know it.

One night, things were just going terribly. People were coming into the hospital with stab wounds, fatal car accidents; you name it. I didn’t have much time for anything.

Just as I was about to catch a break and put my head down, I got a text message from an old friend. I hadn’t seen him since my training years in Texas, but his brother was at my hospital. His wife had experienced a stroke and needed immediate attention.

It was very late at night and coincidentally I was there the same night. I went down to the lower level of the hospital where very few people would be at that time of night. And there he was. His brother was sitting alone, in a waiting room, while is beloved was having her brain scanned.

And at that moment, two people who have never met each other, linked by a mutual friend, were able to sit down and talk. We talked about sports, about raising our kids, and the frailty of life. We ate Oreos, I wished him and his wife well, and went on my way.

Walking back to my room at the hospital, I stopped to look and observe some more paintings.

“Ahmed, is that you? What the hell are you doing?”

A fellow anesthesiologist and buddy of mine, Justin, also working overnight, saw me stone-eyed, gazing at the wall-art, and almost didn’t recognize me. I told him what I had been thinking, and he said he could relate. He pulled out his phone and shared something with me called, “The Dictionary of Obscure Sorrows.” In it was the definition of the word, “sonder”:

… the realization that each random passerby is living a life as vivid and complex as your own — populated with their own ambitions friends, routines, worries and inherited craziness-an epic story that continues invisibly around you like an anthill sprawling deep underground, with elaborate passageways to thousands of other lives that you’ll never know existed, in which you might appear only once, as an extra sipping coffee in the background, as a blur of traffic passing on the highway, as a lighted window at dusk.

Glancing over at family members laying on uncomfortable couches, half-covered by thin blankets, trying to get a wink of sleep as their loved ones yearn to heal in a seemingly cold place, you get the sense that they are homeless for the night.

And at that moment, I am just an extra, sipping coffee in the background, a lighted window at dusk.

Ahmed Zaafran is an anesthesiologist who blogs at DrBeen.