No Surprise Quizes
At the beginning of the semester, a college journalism professor promised his class that he would never given them an unannounced test. The students greeted this revelation with general approval. You can imagine their surprise when, a few weeks later, the professor began the class with a pop quiz. When the students protested, the professor said that he had indeed announced the quiz -- in a small ad at the bottom of the last page of the local newspaper's Sunday classified advertisements section, under the "Personals (Homosexual)" subheading.
Behind the Legend
In 1946 a journalism professor at the University of Carolina made an announcement just as described and did indeed have a surprise quiz a few weeks later. Where the stories differ is that the real professor had a method to his madness -- he had instructed his students to always read the morning paper before coming to class, and therefore had a reasonable expectation that they would have seen the note. In fact, just to make sure that anyone who read the paper saw the announcement, he included it as part of a fraudulent ransom note that said the Governor's daughter would be killed unless $1,000,000 was delivered to a secret location and the note ran on the paper's front page.
The professor retired to South America soon after.