A brash and cocky physics student

I was back at the high school I went to, but at my current age.  For some reason, I had to re-take the Physics final from my Dad's class.  (He taught me for Freshman Physics, and still teaches the course at the school.)  I went in to the final without studying and was very confident.  When I got it, somehow I recognized all the questions as the exact same final that I took back in 1997.  I breezed through it, extremely confident of every answer.  I don't know why it was important, but it's like the whole point of doing this was to get a better grade than I had gotten on the test when I took it for the class.  I turned in the test and left.  A few days later I was bugging my Dad, asking if he had graded the final exams yet.  He hadn't, but said he would be soon.  I hadn't let him know how great I felt about the test.  I couldn't hold it in any longer so I just told him that I totally aced it, that I'm positive I got every question correct, I'd be shocked if I had even missed one.  I told him that my memory was just so good, that giving me the same exam twice was a mistake on his part.  He asked me if I was "sure" that I had beaten my old score.  I assured him that I had.  I didn't know what my old score was, but was thinking probably somewhere in the A-/B+ range.  He pulled out my old exam, and the score on that one was 110%.  I don't know how that score was even possible, because he's not one to give extra credit on tests, let alone final exams.  The test I just took had no extra credit opportunities, so I was surely going to fall short.  I didn't stick around to see what I got on the final that I just took.