Me?
OK, I'll answer this honestly, because I'm still clarifying this point myself. I keep having to edit this post because I have exactly the opposite problem of "can't think of an answer to this question".
I definitely have an answer to this question, I just don't know if it's the *right* answer.
Why? Because my interest in medicine is completely, utterly and shamelessly selfish.
It isn't "to help people" or any of that because there are easier ways to do something that helps people. There are too many easier "helpful" jobs to get into, to justify becoming a doctor to do it. And it's not worth it for the money considering how much money you lose due to malpractice insurance, taxes, paying off student loans, etc. I'm also not doing this because I just really love and crave patient contact, because if that were *all* I wanted, I could become a nurse and get that. Realistically, I know that I could do a low-contact type of job, or go the MD/PhD route and do research, if I hated the contact.
Here's the deal: I keep having to edit this post over and over because I just can't write this and not make it a *novel*.
Basically it boils down to, I'm just a person with an eccentric, bizarre lifelong clinical interest in humans, their bodies, and what makes those humans and their bodies tick. I want to know more. I need to know more.
I crave this knowledge like some people crave sex or crack cocaine, and the more I know, the more I want to know. I want to know so badly it keeps me up all night reading and finding out more. I want to know so badly that I'm willing to torture myself going through all this crap to *get* that knowledge. Some people are willing to sell their bodies for crack or smack. I lived around those people, growing up. I've seen their cravings, their desparation.
I crave this knowledge almost like *that*. Just as someone might get some high-grade heroin to mainline if only they sell their body on a street corner just one more night, I feel that perhaps if I stay up all night every night doing math (which is torture for some people; and remember, I'm a high school dropout, and all my life, people said I "couldn't learn"), I'll be able to get this knowledge in the most direct way possible. Becoming a doctor is the way I will get the "mainline" of the knowledge of the human body and how it ticks.
I've been passionately obsessed with medicine (and bioscience in general) all of my life. Insanely, eccentrically obsessed to the point of being "that weird kid" (there's one in every classroom...) growing up.
I am a non-traditional student transitioning over from being a computer person.
It may be that I am too eccentric to be a doctor. I have a bit of the "eccentric scientist" or "obsessed detective" personality, except that I am too extraverted to be either a pure scientist. I like being around people. But I will regret it the rest of my life if I don't give medicine a shot. I'd rather try and say "I tried it and didn't like it" or "I tried it and failed" than say that I didn't try, I won't respect myself if I don't try.
If I don't end up becoming a doctor, then I'll be associated with scientific research or public health in some form. I'm going after my EMT-B certificate this summer, so we'll see how I like being around body fluids and stress in real life. Med school or not, I'm still getting out of here with a bio degree, and probably doing something related to the academic study of medicine if not the practice of it.
I don't know if these are the right reasons. It could be that I'm exactly the *wrong* person for the job, that I would be too clinical or curious to be a compassionate person.