a story in which my smartest student loses all of my respect

The Story for which he will be ridiculed for the rest of the year and, if I have anything to say about it, quite possibly the rest of his life:

Matthew, the student who scored a 105 on my physics midterm, which was 13 points higher than the next highest grade and 71 points higher than the lowest grade (while taking a scantron midterm exam): "Um, I put down B for #52, but I want to change my answer to C. How do I do that?"

The response: Um, see that pink rubbery thing on the end of your pencil? Rub that over the "B". It makes the pencil mark disappear, and it's almost like you never wrote it. Pretty clever, huh?