I have always wondered what anesthesiologists or radiologists said during their interview for medical school admission when asked "Why do you want to be a doctor?" I imagine most of them answered, "I want to help people", or "I like people." I also imagine that if asked why they chose to become an anesthesiologist or radiologist they would reply, "I don't like people." In other words, they prefer the patient to be asleep most of the time, or in the next room.

What might a public health practitioner say? Perhaps, "I like people, I just like dealing with them from afar."

During my medical school interview, I had the spiel memorized. I was even going a step further, applying to a combined MD-PhD program. I was going to find cures to rare diseases and deliver them to my patients. I was going to be the bridge between lab and clinic, between bench and bedside. I was going to personify the classic triple-hatted medical professional: a scientist, a clinician, a teacher. I would do it all, and do it all very well.

During my medical school clinical years, however, I realized that each "hat" presented its own challenges. Being a successful scientist would demand endless hours of experiments and writing. I would be competing for notoriety and funding with scientists who were able to spend all of their time in research and did not have clinical or teaching responsibilities to fulfill. Being a leading clinician would involve years of training and seeing patients. Likewise, teaching would demand time and effort if I was to do it well.

It became evident that to be successful, I would need to spend most of my time in one area and commit enough time to the other two in order to achieve basic competency. I initially explored basic science as a primary occupation with clinical work second. However, it became evident that to bring a therapy from the lab to the clinic would involve time, work, and quite a bit of luck. Cancer has been cured in mice more than twice " a promising agent in the lab is still a long way away from becoming a reality for human patients. The best I could hope for would be much effort with the hope that I would have something useful a few decades later.

This timeline did not suit the patients I met during my training. They needed help now. They did not need an elusive cure to a chronic disease. They did not need a fancy answer to an age-old question. They needed access to existing medicines and therapies. They needed ways to understand how to best care for themselves during times of illness and health. Their children needed protection from their parents" ailments, before another generation was subjected to mistakes of a previous generation. They needed more than I could offer them as their physician. That is how I decided to enter public health.

The decision was complete when I was accepted into the Epidemic Intelligence Service and hired by the Centers for Disease Control and Prevention. Most of my clinical colleagues shook their heads. Why give-up being a doctor after all this training? Why not work in a clinic and do research on the side? What good could I possibly do sitting at a computer for most of the day? What a waste.

I found solace in a concept from my Jewish heritage, tikkun olam. Literally, it means "repairing the world". Figuratively, it refers to social action. Traditionally, Jews are encouraged to contribute to tikkun olam however they can, through volunteer work, charitable donation, or other means. In my mind, working for the public to improve health is a means to help remedy inequality. It is a way to provide for people in need with the means we posses now and not future inventions. It is how I hope to contribute to the "repair" of the world.

For the remainder of my training, I focused on mastering skills that I would need to work in public health. To my surprise, all aspects of my training were important. I needed to be familiar with medical practice, to help identify and diagnose disease. I needed to be familiar with the basic science of microbes, to help control and prevent disease. I needed to learn different ways of communication so as to educate professionals as well as the public about disease. As it turned out, changing between the three hats of medicine would not do. Instead, I learned to wear all three at all times, to utilize the three-cornered hat as a public health practitioner.

I believe that applying scientific methods to public health practice will generate optimal solutions to problems affecting the world's population. In this way, I feel I can best utilize all aspects of my training as a physician, basic scientist, and epidemiologist. Who better to design means of achieving health than a former healthcare worker? Who better to devise means of proving effectiveness of programs than a laboratory-trained scientist? Who better to explain the needs for improving global health than an epidemiologist?

I still like people. In fact, I think I care about them more than I did as a medical student. I no longer think about each patient in his allotted 15 minutes. I now think about large groups of people, of populations of towns, counties, states, and countries. I think about how they currently are affected by communicable disease. I think about how I can help protect them from disease. I think about ways to help them be healthy today and for years to come.