To get the wrong end of the stick: The teacher has the right end of it.
A penny for your thoughts: What you ask your friend when you do not know the answer to the teacher's question.
A fool's paradise: School
Misfortunes never come singly: Especially on a Monday morning at school.
As the crow flies: Straight to the office.
[Philip Boshof, Yearbook 1974, std. 9B]