Personally, there are many different reasons as to why I want to be a physician.
As a freshman, I started volunteering at a hospital to fill some free time. There was (and still is) something captivating about the subculture of medicine. The sterility of a hospital, the professionalism, and patient interaction, were some of the more notable qualities that piqued my interest. Eventually I started researching the career to see if I even had a chance. I read into every specialty, shadowed physicians, and volunteered in more departments at the hospital. Also, I learned how long it would take to become a doctor, and to be honest, the competitiveness of it all attracts me even more.
Practicing medicine is also a wonderful opportunity; with an array of specialties, there seems to be a fit for just about anyone. Personally, I have become very drawn to surgery; I think the ability to physically heal an ailment, with almost your bare hands, is something extraordinary. Moreover, the ability to work with a team, to delegate, and to inspire, are other perks of the job.
To recapitulate: the qualities of medicine which allure me are: environment, professionalism, diversity, scientific applications, and the skills to heal another human being.