At my school we took our school pictures on the first day of Kindergarten. My mom had me picture perfect, with a pretty dress, a nice hair cut, and a brand new backpack. The day before I chose to cut my own hair and the only fix a hairdresser could make was giving me a bowl cut. So instead of a picture perfect first day, I look like a little boy.
As a teacher I'd say this fits pretty well: Nothing that is planned for the first day of school will ever go the way you want it to, in fact, you might want to cry at how completely opposite it turned out, but one day you'll look back and laugh at what came of it.