We learn best by example--this adage is probably as old as teaching itself. In my own classroom, I have found that very often the students learn best from the "negative" examples. Perhaps, this shouldn't come as a surprise at all. After all, we don't react strongly to the norm--but an obvious deviation from the norm may attract our attention and make for a great teachable moment. And, if the deviation happens to be either scary or funny, the added emotional impact can create a truly powerful and lasting memory in the minds of the students.