When you first start going to school, as a little kid, all the schoolwork is confined to the school. When you get out, you don't have to worry about it until you have to go back. However, you don't appreciate it because you don't understand that you will soon lose these reasonable boundaries.
Namely, as you start to get to be a big kid, the schoolwork starts to overflow into the time outside of school. They call this 'homework.' This is a miserable state of affairs and truly unhappy.
Finally, you get to the point that coincides with its opposite at the beginning, and the occasional trip to school becomes a break from schoolwork. The original and blessed boundaries are restored, if in reverse.