A well educated professor told his students that 50% of their grade would be based upon the difficulty of questions that would stump the professor in class and 50% based upon answers on the exam. Not one student could stump the professor, but they did a phenomenal job trying to do so.
Throughout the term, many of the students lost focus and put too much attention upon thinking up difficult questions to ask. So when the exam came, many of the students were poorly prepared. One student decided to take a High School approach by writing everything he could think of that was even remotely related to the subject of the question. His hope was to include so many words that somewhere in the fat, an answer to the question might ebb towards the answer being sought after. He wrote feverishly for the entire 2 1/2 hr exam and had about 10 pages of text when he was done.
When the exams came back, the student's friends read the professor's comment by the professor and bent over laughing.
In red letters on top of the long padded exam, the prof wrote a great one liner, "You're answer is not right. You're answer is not even wrong."
Here is what the prof was really saying. When somebody gives an answer to a question, which are "right" or "wrong". Saying it is wrong is at least acknowledging that something has been said.
When the prof said, "It is not even wrong", he was basically saying that the students' answer didn't even rise to the dignity of an error. This is because you can only say something is wrong when something has been said.