The following passage was my response to Columbia's question last year. I felt that it was more succinct and eloquent than anything I could have written myself, so I didn't feel weird quoting it. Perhaps, in your own reading of doctors' experiences, you'll read something that will concisely summarize your own anticipations about your medical career!
"It's the humdrum, day-in, day-out, everyday work that is the real satisfaction of the practice of medicine; the million and a half patients a man has seen over a forty-year period of weekdays and Sundays that make up his life. I have never had a money practice; it would have been impossible for me. But the actual calling on people, at all times and under all conditions, the coming to grips with the intimate conditions of their lives, when they were being born, when they were dying, watching them die, watching them get well when they were ill, has always absorbed me.
"...From the very beginning that fascinated me more than I myself knew. For no matter where I might find myself, every sort of individual that it is possible to imagine in some phase of his development, from the highest to the lowest, at some time exhibited himself to me. I am sure I have seen them all...This, in the end, comes perhaps to be the occupation of the physician after a lifetime of careful listening."
-From "The Practice" in _The Autobiography of William Carlos Williams_
As for the "additional information" section, you can give them pretty much anything you want, from your AMCAS essay (which you can and should reuse, retitled of course), to your resume, an expanded list of class titles and extracurriculars (since there semed to be little space for these on the online form), etc, just as long as it's all part of the same file (you can only upload one, if I remember). Just don't go too overboard... 😉
Good luck-
