First Day of School Anxiety

Today was our 9-year old's first day of school. 4th grade seems like such a huge leap at that age, and tends to cause much anxiety on elementary students everywhere.
I wonder why the start of the school year leads to so much consternation and dread for such a large population of students? It seems to be the same, year after year. I had worries, my friends had worries. What the heck?

How many of you had the obligatory dream sometime in August where you were late for the first day of school?

Or got lost somewhere in the school building?

Or couldn't get your locker open?

Or forgot your lunch, missed the bus, ended up sitting without pants in the classroom (library, homeroom, bus stop, etc.)?

Let me know which of these sounds familiar, and what you think caused your own measure of dread.

Image by laffy4k via flickr