(I'm going to go ahead and assume that this thread is a joke, and if not, try to salvage it as Responses you should never give to the interview question "why medicine?")
1. I'm building a Frankenstein-type monster and fresh body parts are hard to get in other careers.
2. I have a medical fetish.
3. I like to read medical books and figure I might as well get some money out of that.
4. My parents forced me.
5. My parents didn't want me to go to medical school, and I'm rebelling against them.
6. It will put me in a position to abuse the naive trust of society. Muahaha. (N.B. evil laughs are never appropriate during interviews.)
7. I wish to unite man and squirrel through experimental surgery.
8. I need a job that will allow me to support my nine thousand cats.
9. I'm sure it will make it easier to get dates.
10. The drugs, mainly.