In going through papers I am trying to trash...I kept one from a student, Leonard Sweet, who had written a poem at the bottom of his calculus exam when he turned it in:

    Now I lay me down to sleep,

    This test is long and very deep,

    If it should end before I wake

    Just give my arm a gentle shake.

Some things you just can't throw away.  I handed the exam back with a poem I made up for him:

    In life there are some things, it seems,

    We need to do before we dream.

    Next time please dream before you test,

    Or you may fail.  (I do not jest.)

That entire class was one of the most fun groups I ever taught.  I liked them, and they liked me as well.  A satisfying experience.