There are normally a lot of jittery stomachs the first day of school. New teacher, new class, new school. There is an unknown in that. And then for some students there is total readiness. But in both cases there is feeling that students like and need. A feeling that may not be there for the summer.
It is the knowledge that there is structure. They know what they are doing during the whole day. They know what comes first then next and so on. They know what is expected at school, and for the most part strive to to do. There is a schedule posted, (hopefully, a good teacher would have one up) which brings comfort to the students.
As I write this that might be why kids miss school during the summer. They may not say it, but inside somewhere they do. Even for us adults we like to know what is going on and when it is taking place. Kids lose that structure during the summer, (for the most part.) And more than likely don't have a schedule posted of their summer day.
Are kids ready for school to start? Maybe more so than adults. Structure is a big thing. Just the other day I had a student tell me they were ready for school because of just this reason. Structure