I am always amazed that more students do not twig to the fact that a tiny bit of appropriate humor included in the margins of a response almost always puts the person grading in a better mood right before said grader is going to read the student's response.

And that bit of humor is positively awesome.

I'm also amused that it's entirely possible that somewhere else on a journaling service, a student is saying to his or her friends "So, how awesome is it that my prof used these names in an exam question on . . ."