Thanks, that perspective really helps. I know I will be anxious enough with the interview in general so I was worried about that particular question and not just how I answer it but my body language and confidence when answering it.
I have already thought of saying something like: "I dont want...
Long story short, I did poorly in undergrad and failed and repeated 5 important classes in my major. I had terrible anxiety and off and on again depression throughout college which was the root of the problem.
I managed to get into grad school and do very well which does undo some of the damage...