Last week, with my youngest child about to graduate from high school, I made my last school lunch.

Twenty-one years, three children, and 5,000 brown bags (by my husband's calculation). That's a lot of peanut butter.

I wasn't teary-eyed, or even sad or sentimental, really. I was more in a state of disbelief - that so much time had passed, that those little kids were now so completely grown, and that I had endured, and even come to enjoy, the nagging little morning task of making lunches.

I had my routine, making sandwiches on frozen bread, so they would stay fresh but thaw in time for lunch. I had even organized my kitchen so the cookies and granola bars were in the cabinet over my work space, and the brown bags and plastic baggies in a drawer below.

Like sitting down to dinner, the making of the lunches had become a ritual, a time to connect. While the kids shoveled down cereal, I would assemble their midday meals, chatting about what was ahead that day, what was needed in their brown bags.

For a very short time when they were little, I could pack anything I chose, and they were happy: all-natural peanut butter on whole wheat bread, homemade cookies, fresh fruit, carrot sticks, red pepper slices, and a no-sugar-added juice box.

But soon enough I was undone. A treasure trove of junk called to them from all the other lunchboxes in the cafeteria: Tastykakes, Fritos, Cheetos, fruit snacks, anything chocolate.

I quickly learned: I was packing my kids lunches of shame. No one wanted to trade with them, no one envied their treats or their boring juices. They were humiliated by the wholesome contents of their bags.

And so I relented and occasionally bought those horrid lunchbox treats I remembered begging my own mother for (although my kids will say I didn't buy them nearly often enough).

But as they grew and many classmates opted for hot lunch, my kids always stuck with ones from home. I don't think it was out of loyalty to me, but more out of a desire for predictability.

In middle school, as the world changed around them, maybe there was some comfort in the same old sandwich and cookies and fruit and carrots and granola bar every day. It was something they could always count on.

The boys asked for plain peanut butter almost every day until they got to high school, and then their need for meat was specific: corned beef on rye with mustard for one; buffalo chicken with Cooper sharp cheese for another.

My daughter was (and still is in so many ways) more complicated. We did bagels and cream cheese for a while, then turkey and cheese roll-ups. We did tuna fish and egg salad in her vegetarian phase; yogurt, peanut butter and banana, soy nuts, even salads with individual salad dressing packets - where did I ever find those?

And I can't say it wasn't a pain. I can't say there weren't times when I lay in bed before drifting off to sleep, wondering if there was another can of tuna in the pantry, or if I had finished the last loaf of bread in the freezer.

But in the end, and without my realizing it, that small job of making lunches every morning had become something I valued. It was a way of staying in their lives. I was giving them a little piece of me to carry with them into their day. It was my way of saying: Eat a good lunch, your mom loves you.

And as they grew and matured and became so independent and capable, as their skills at soccer and calculus and technology so far surpassed mine, they hardly needed me to make their lunch every morning.

What had changed was that I needed to keep doing it.

I wanted to still have a role, still be needed, still be a part of their day, still be there, reminding them: Eat a good lunch, your mom loves you.