Proof:
If you do not know the correct answer to a question commonly answered correctly by second grade students, you are stupid
There is a question that is commonly answered correctly by second grade students that you have not heard
If you have not heard a question, you cannot know the correct answer
There is a question commonly answered correctly by second grade students to which you cannot not know the correct answer
You do not know the correct answer to a question commonly answered correctly by second grade students
∴ You are stupid
Q.E.D.