"There's a Niche for Every Nuthatch"
When I speak with medical students about choice of specialty, I often invoke an ecological analogy. A healthy forest has myriad ecologic niches. The great horned owl and the nuthatch happily coexist because each is adapted to its own niche and stays in that niche. The nuthatch doesn't try to swoop down and grab a mouse in its talons, nor does the great horned owl try to creep up or down a tree trunk. They are good at what they do, and they don't try to wander outside the part of the microenvironment for which nature has created them. Medicine is like that. There are many specialties, and the trick is to find the one that fits you.
Here are some of the questions I ask them. Do you enjoy spending time with patients? Not everyone does. Most people who go into medicine think they will like direct patient care, with the attendant demands upon time, emotional energy, and empathy. Some find that it is more than they bargained for. If you like direct patient care, then Family Medicine, Internal Medicine, OB/GYN, Pediatrics, General Surgery, Psychiatry and various subspecialties such as Oncology are great choices. If you don't like direct patient care, there's no shame to admit it. Don't let yourself get boxed into one of those specialties. We need pathologists, radiologists, and medical researchers too.
Are you the kind of person who likes to know something about everything, or the kind who wants to know everything possible about a narrowly focused field? If you are curious and interested in everything, then become a generalist (such as General Surgery, to take an example from my area of medicine). If you yearn for complete mastery of your field, go into a subspecialty (such as Endocrine Surgery).
Do you want an academic career (such as mine) or one in private practice? Academics nowadays requires specialization. Private practice in heavily populated areas does too.
Where do you (and your family if you have one) want to live? If you want to return to a rural part of the state, you need to think strategically about what specialties are needed in that area. Even a small rural hospital needs a good pathologist, but it needs a general surgeon more than it needs a surgical oncologist.
There used to be a half-humorous algorithm that we shared with medical students. If I find it, I'll post a link. If memory serves me correctly, it had things like: Do you like to work in the dark (Radiology) or not in the dark (anything else). If you went down the entire algorithm it matched you pretty accurately with a specialty.
Oh yeah, I should add, I try not to call the med students "nuthatches" – unless you are a bird-watcher, that might be taken the wrong way…