In 1984, as a 17-year-old high-school student in Israel, I was a member of a youth movement that focused on study, civic work and preparation for military service. Our graduation ceremonies often featured big fires, intended to dramatize our patriotic fervor. That year, some of our leaders had brought back military supplies to help make the blaze especially intense.

One Friday afternoon, as we began putting away these materials, there was an accident. Nobody knows exactly what happened, but a spark must have been struck somewhere. A large magnesium flare—the kind that the Israeli military uses to light up a battlefield—exploded right next to me. In a moment, I was engulfed by flames.

The fire nearly killed me. About 70% of my body was covered in third-degree burns. In a matter of seconds, my life had changed irreversibly. Looking back now, more than three decades later, I realize that my awful new situation had one unexpected and positive effect: It began my career as a serious observer of the peculiarities of human behavior.

The explosion marked the start of a three-year period of hospitalization and surgeries—first in the emergency department of Beilinson Hospital, then in Tel Hashomer Hospital, both near Tel Aviv. I’ll never forget the day, perhaps four months after my injury, when I first saw myself in a full-length mirror. Before the accident, I had been a decent-looking teenager. But that day, I saw something completely different. My eyes were pulled severely to the side. The right side of my mouth and my nose were both charred and distorted. So was my right ear.

Was this really me? It was hard to see, believe or accept. Why was I still here? What would my future be, looking like this?

The burns and their treatment caused me extreme pain over a long period—a kind of pain that is more intense and lasting than almost any other medical condition. But since I had little else to do and badly needed distraction, I began to notice and record things.

For example, every day, I had to have a soaking bath that involved removing my bandages and scraping off my dead skin and flesh. The nurses would rip off the dressings all at once, without a break. It was excruciating, but the nurses insisted that tearing the bandages off was the best way.

One day, one of the nurses allowed me a bit of control over the process, and I found the treatment somewhat more tolerable. This made me wonder if having more control over the process would be better in general, but given my helpless position, I had little influence over the way I was treated.

After years of treatment, I left the hospital and went to Tel Aviv University. I decided to study psychology. My harrowing years had left me deeply interested in understanding how we experience pain and in the experimental method.

So I carried out laboratory experiments on myself, my friends and volunteers, using moderate (and safe) physical pain induced by heat, cold water, pressure and loud sounds—even the psychological pain of losing money in the stock market—to probe for answers. I learned that there are better and worse ways to deliver pain—and that my nurses’ methods hadn’t been the best ones. (One should remove the bandages slowly, not rip them off, and one should start from the most painful parts, then move toward the least.) If my nurses, despite all their experience with burn victims, had erred in treating the patients they cared so much about, other professionals might also be misunderstanding the consequences of their behaviors and make poor decisions.

Soon, I found, my personal and professional lives had become intertwined. For years, I felt the burden of my scars: the unending pain, the odd-looking medical braces, the pressure bandages that covered me from head to toe, the feeling of having gone through some kind of weird door and of living separately from the day-to-day experiences of my previous self and other “normal” people. I’d become an observer of my own life, as if I were watching an experiment on someone else—and I looked anew at other people as well.

This new approach became central to my work. Remembering the placebos given instead of medications during some treatments, I conducted experiments to explore the effects of expectations on painful treatments. (They can dramatically change our experiences—and even the intensity of the pain we feel.) Remembering how it felt to be given difficult information in the hospital, I tried to figure out how best to break bad news to patients. (Slowly, and in steps.) I kept finding topics that crossed the personal/professional boundary, and over time, I learned more about my own decisions and the behavior of those around me.

I saw people who managed their suffering and triumphed, and I saw others who caved in to fear and terror. I tried to take apart mundane daily activities—about why we shop, drive, volunteer, interact with co-workers, take risks, fight and behave thoughtlessly. And I couldn’t help noticing the intricate fibers that entwine our romantic life. (Fortunately, I never lost my sense of humor.)

All these questions began to weave their way into my research. I grew increasingly adept at observing how people went about their daily lives, prone to wonder about human habits, eager to explore the reasons for our behavior and motivated to find ways to make us behave slightly better.

My accident happened more than 30 years ago, and if any good came out of it, maybe it is this: I like to believe that the disaster and its aftereffects made me better able to understand myself and others. Maybe I’m rationalizing. We human beings do that exceptionally well: By trying to see something awful in a more positive light, we’re able to make sense of it, or at least make it more tolerable.

After years of writing scholarly papers on these topics, I started writing about my research and its implications in a more conversational, less academic way. And perhaps because I described how my research grew out of my own struggles, many people started sharing their personal challenges with me. With experience (warning: second rationalization coming), I got better at answering their questions. And I would like to believe that my advice was even helpful sometimes.

Don’t get me wrong: I don’t think that my injury was worth it. I have spent every day of my adult years in varying degrees of pain. I have endured, over and over, the dysfunction of the medical system. I have been exposed to an astonishing number of medical procedures and odd human interactions. I am more comfortable in public these days, but my scars still make me feel out of place in most social circumstances.

But—whether I’m rationalizing or not—I did learn important lessons from my injury, my time in the hospital, the years that followed, the research that emerged from my ordeal, and the questions and challenges that people have shared with me over the years. These have become my microscope on life.

My latest book, Irrationally Yours, which is based on my Wall Street Journal column “Ask Ariely,” was recently published by HarperCollins. See this article on the WSJ here.