I haven’t been a high school student or teacher for many, many years. But the day after Labor Day I forget that fact. For me this day will always be the first day of school and the last day of summer, and therefore worthy of a quick sigh, a backward glance. Even though in steamy July I might long for the clean page, the crisp new start, even though this season will, eventually, energize me — for now it’s bittersweet. The crickets chirp more slowly, the morning air is brisk. Last night I wrote names and numbers on emergency contact and other school forms. Seems like everyone has homework before school begins — even parents. My lesson is brief but painful: Summer passes more quickly every year.