Well, I am one of those with great stats but no acceptances last year (5 interviews). I just had my first interview this cycle at UNC and I feel great about how it went. Last year, I was very nervous at my first few interviews and just was not confident in my interviewing skills. I think I said "um" a lot and hesitated on some questions last year. I also stumbled/stuttered my sentences a bit last year when I couldn't figure out the correct words to say. Also, I was kinda stiff and didn't show my personality/smile as much as I should have. This year, at my interview, i was just relaxed and smiling and laughing during the interview. I answered the questions fluently (without hesitating or saying "um"). I just told the truth about myself in a very conversational manner. So my advice, Don't be nervous at all. Almost all interviewers are nice and aren't trying to mess you up on purpose. They want to see that you can be social and professional. Obviously, read the common interview questions and have an idea of what you will say to ANY type of question you may hear (especially if you don't know the answer to a question). Good luck!