In which I come dangerously close to discussing workplace issues

Grading the first batch of quizzes for my American lit survey (1865-1920) I'm floored, as I am with every first batch of quizzes with how little of what passes my lips or flashes up on the overhead actually makes it, whole and unadulterated, into some students' heads or onto some students' looseleaf. One gets used, of course, to having "minstrel show" come back as "menstrual show"--even though one wonders how a female student--young enough to still feel self-conscious or inconvenienced or possibly even relieved (depending on circumstances) by her monthly onset--can calmly sit thinking I'm talking about popular public displays of (presumably) menstrual blood (in the nineteeth century! in the genteel South!) and not raise her hand to ask a clarifying question, but after awhile one's amusement becomes forced and one's laughter hollow.