For me, the clearest indication that my son's childhood as he knew it was a thing of the past started with the cupcakes.

At a middle school orientation two years ago, I was the ridiculously out-of-touch mother who raised my hand in a crowded gym and innocently asked if it was still okay to bring cupcakes to celebrate a birthday in sixth-grade.

The crowd laughed. The principal rolled his eyes. I blushed and learned an important lesson about this next stage of life, which I've dubbed The Age of Embarrassment. It's time for parents to back off.

Parents are all over the best elementary schools, organizing fund-drives and bake sales and penny drives, going on field trips, and yes -- carrying in those giant tupperware boxes filled with cupcakes.

Not so in middle school. Two years ago, I took my sixth grader on the first day. On the second day, I walked a few blocks behind. (Could anything be worse than being seen with an actual parent?) and after that, he traveled mostly with his friends or alone. Now, if I want to stop by the school, I can't take the same entrance.

Birthdays? Forget it. He doesn't want anyone to know.

Not all middle schoolers become this self-conscious, of course, and none of this means middle schools don't need support from parents -- they do, more than ever! My best advice to soon-to-be middle school parents is to ask other parents how they handled the transition -- and find out from the principal, parent coordinator and the PTA what's most needed. Trust me, there is plenty to do.

Today, we said goodbye to my younger son's elementary school, to teachers, parents and staff we knew for so many years they felt like family. There were hugs, tears and presents and then it was over.

It's almost time to pack up all the stuffed animals and Dr. Seuss books too, reminders of the elusive and transitory nature of childhood. But first, though, I'm going to bake a batch of cupcakes. They may not be for a class party, but they'll still fill the kitchen with the smell of childhood.