After being a substitute teacher for 4 years, I have learned that their are some days you should never work on (of course, I do anyway).
1. The day before any major break (Thanksgiving, Christmas, Spring Break, ect). The students know that you aren't doing any "real" work so they are already "on break".
2. The day after Halloween - the kids have been up to late and have eaten too much candy in order to be able to focus on anything.
3. Today (Valentine's Day) - the kids (especially in elementary school) are to excited about the candy and everything to focus. Once again they have too much sugar during the day with the candy they get from teachers and friends to be able to focus on anything. Even if you take up their stuff until the end of the day like I did today, they still have cupcakes that are brought in at parents for lunch and candy that other teachers give them. Even without that they are so excited about what is in their bags that they can't concentrate on their work.
Even so, I work with some great kids!!! They might be a bit crazy somedays, but they are some of sweetest kids! I love my job, even on the days that are "hard"!!!