A doctor? Impressive, RSK! I suggest you practice answering these types of questions OUT LOUD as many times as you are able to, so when you go in to interview you will be more relaxed. It might be helpful to practice with a videorecorder so you can see how you will appear to other people. How are your grades, especially those in Biology and Chemistry? (What was your bad grade in?)

I don't suggest you tell them you spend your free time on loveforum. (haha)

Good Luck; I'm sure you'll be fine!