You mean you didn't get asked this very question in interviews? 😛
Anyway, to answer your question: I didn't go into this at all hoping to save the world or even make some earth-shattering new development. What I like is to interact with people, and help them in the process. Yeah, I could do this in a lot of ways, but I've found that I'm rather good with the scientific subject matter that is medicine.
I'm just out here trying to make some kind of a difference in my little corner of the world, one person at a time.