Imagine walking into class one day and with no warning your teachers, (who are a little strange anyways) are dressed strangly, making strange noises and giving out candy for no reason. Then they have you cut a face into a pumpin and put a candle inside.
We had a big Halloween bash at my school and dressed up and decorated the school and carved pumpkins. (The kids kept asking, "Are we eating the pumpkin?" I said, "Um, I guess so, if you want you can eat the parts we cut out.") My favorite part of the day was when kids would come in late. I took the first ten minutes of each class to explain what Halloween was and what we were doing and so when a student came in late I delighted in acting completly normal while scooping the guts out of a pumpkin. "What? Is this not what school is usually like?"