I felt that UNC's whole application process for very psychological. From the supplemental to the faculty interviews I was hit with odd questions exploring the way I was programed. I know they want to see how you handle failure. Do you freak, work harder, accept it, refuse to accept it, etc... Having been in dental school for a couple years I can help you all answer that question. ACCEPT IT. It happens. You don't need to work harder as a result, just learn from it. In the clinic, you may screw up a prep. Fix it anyway possible and move on. You may fail a test. Oh well, learn from your mistakes and study better next time. They don't want anxious perfectionists. They want down to earth, confident students. So don't go babbling about how that 18 in RC is not acceptable and you wish you did better. Just say you had a good grasp on the information as a whole and just slipped up in whatever section.