I subbed for a high school science teacher.
I had to give a test to one class period. The kids were furious. They claimed to have been told the test would be tomorrow. During the 15 minutes I gave them to study beforehand, I heard many of them vowing to each other that they would "fail it on purpose, just to get back at her." The logic there is astounding.
On a side note, I have just finished getting signed up with a second third-party subbing agency. Many of the schools are as close or closer than some that I have already been working at (I've been driving as much as 50 miles one way to get work). These schools also pay more. Assuming I got the website set up correctly, I should be working in a brand new school tomorrow.