It shouldn't be difficult to answer that question...say something about your life, and remember to say something that they will remember.
I would refrain from saying
"I was born and raised in Virginia, and early on I knew I wanted to go into medicine. When I was a teenager I started to understand, through project X and Y, that medicine was the career for me. I went to undergrad at Z, graduate with a.bc, had some wonder EC's in college."
Nothing really interesting about that.