It's that time of year at my son's preschool when we parents cram into the fellowship hall and jockey for a glimpse of our children singing songs such as "This Little Light of Mine."

This year, my son's final year, he was thrilled to be a lantern fish, though he wasn't exactly sure what that was. When he finished singing, everyone filed back to the classroom to gather remaining craft projects and to say farewell.

I felt a tiny tug. Because he's graduating.

As we headed out, I watched all of his preschool classmates bop away, knowing that next year they will head off to different elementary schools. I'll miss these little friends of his.

Friends like Thomas, whom we met in the 2-year-old class, my son's first separation from Mommy. That year, my son cried for me every day, all day, often until the director summoned me to get him. Thomas hid in the cubbies.

The boys became friends, bonded over separation misery.

Now they are the big boys of the school, and Thomas' mom and I are just happy if they don't get in trouble for wrestling on the floor during story time.

My son even has taken to performing a rather loud imitation of the crying babies down the hall from his classroom. I suppose he's grown so much older and wiser that he's forgotten just whose cries used to echo down that very hallway.

When we get home, I pause at his class pictures hanging on our refrigerator.

In his 2-year-old picture, he's sitting cross-legged on this colorful carpet, his big brown eyes staring miserably up at the camera.

At 3, he's standing with a swagger, hand in one pocket, all serious beside two rows of grinning kids.

And this year, at 4, he's sitting on a chair in front of his teacher. He and all of his classmates are sitting calmly in their seats, clearly following directions. He even managed a tiny smile.

I figure this progression is the whole point of preschool, right? To get them ready for the next journey.

Come fall, he'll move up to a school that starts and ends with the rumble of buses and the clatter of kids racing around with rolling backpacks.

Thankfully, he's excited about going to the big kids' school with his older sister. He wants to ride those buses and climb on a new playground and meet new kindergarten friends.

But for me, his launch into elementary school brings a mix of relief and sadness. This fall, I won't be the primary person responsible for him during most of his day, as I have for his entire life thus far.

In preschool, he's been gone just a few mornings a week. But full-day kindergarten means just that. He'll be gone from 8 a.m. to 3 p.m. five days a week.

So I feel like I'm graduating as well.

When he goes, it will be the first time in 10 years that I haven't had a baby or preschooler at home. And so turns a season of my life, the one in which so much energy has revolved around people so small.

Suddenly, my little guy can dress himself, put on his own shoes, use the bathroom alone, wash his own hair and clean his own room.

And my 9-year-old? I'm just happy she needs me once in a while.

For these 10 years, I have altered my career path so that I could be home most of the day for whoever needed me. I'm incredibly thankful that it was possible.

I'm thankful for so many trips to the park, the aquarium, the bookstore and the library. And I'm thankful for days spent at home just hanging out, playing and learning numbers, colors, letters and words.

So for the next three months, I'll enjoy another crazy summer at home with the kids and their friends.

But come the fall, this house will turn strangely quiet once the bus rumbles away.

And so the question will beg of me: What's next?