The first day of school
On the first day of school everyone is nervous. They don't know who to sit by. They don't know any of the rules, so it's easy to break them. They don't know what their teacher is going to be like, strict or fair. They might have met the teacher but that must have been before school really started. So they could have just been acting nice when they are really evil. But you shouldn't be nervous because your not the only one who might mess up.