One of my students' moms stopped me this morning and asked what I had taught in her son's class yesterday. I couldn't quite remember. She then told me she had asked her son last night what he had learned in school.
"Well, in math we learned about proctology or proctologists or something." *
Then I remembered: I had taught them how to use a protractor.
* http://dictionary.reference.com/browse/proctology
