Quotation fun – What was your worst classroom moment?

In the book, The Ode Less Travelled, Stephen Fry writes the following tidbit about poetry in the Foreward:

Fry wrote:
It seems to many that while there is a clear road to learning music, gardening or watercolours, poetry lies in inaccessible marshland: no pathways, no signposts, just the skeletons of long-dead poets poking through the bog and the unedifying sight of living ones floundering about in apparent confusion and mutual enmity. Behind it all, the dread memory of classrooms swollen into resentful silence while the English teacher invites us to ‘respond’ to a poem.

To be frank, I honestly can’t remember a bad moment in the classroom, probably because I was reading ahead in the text while everyone else was snoring into their desktops. When we studied Chaucer in 10th grade, it was the most fun I’d ever had in English class. The best parts were the raunchy passages; my teacher read from the text in the doorway, ever alert for the footsteps of the vice-principal (a nun) because technically, she wasn’t allowed to teach such a thing in my high school.

So, what was your worst classroom moment?