I waited at the doctor's office staring at nothing in particular trying not to watch the clock. A vision of my teenage son exiting school looking for me flashed through my mind. I saw his face, sagging with disappointment. Not quite in possession of his driver's license, he normally biked to school. Today, I was his ride. His classmates would be elbowing past him, leaping into their cars and peeling out of the parking lot. Others would board parents' vehicles as they pulled through the pickup line.

I read his imaginary text: "Where are you?" and pictured him clear as day standing there alone, waiting, stranded and frustrated. I felt stranded and frustrated, too. The doctor's lengthy delay would produce a ripple effect, causing me to be late for pickup. I took no joy in having a valid excuse.

When a nurse appeared, I cut the small talk and explained my hurry. To her glib Oh it'll be okay, honey. Why don't you text him? I responded: "I told him I'd be there. I made a promise."

Her head jerked. We locked eyes. She felt the weight of my words. She had kids, too.

Of all the phrases that come out of my kids' mouths, "You're late!" makes me wither the most. It's a loaded accusation. And for me, it brings back memories. I was that kid. My parents were both creatures of late, a pattern so normalized it wouldn't have struck them as an issue worth examining.

When I was under their roof, I also normalized their serial tardiness. They were late taking us to school and late to pick us up. Even after I got my driver's license, we carpooled since my dad worked near my high school. I was about my son's age when, slouched against the wall of the school after volleyball practice, I waited for the family car to pull into the empty parking lot. The school's cleaning crew had locked the doors. I was stuck outside. In the age before cell phones, I had no way of contacting anyone. I don't remember the explanations offered for their delay any more than I remember my reaction. The whole scene was both predictable and tiresome.

I wish I had the insight and courage back then to sit my parents down, put my arms around them, and tell them the truth: I know you love me, but when you're always late, it seems I'm not important. But I lacked the maturity to unpack and explain to them why I felt nagging hurt and agitation every time they rolled in after they said they would.

So, I grew indifferent.

It would have been natural for me to carry this habit into my own home, but I resolved not to repeat this pattern of tardiness with my own kids.

Though my intentions are strong, most days, I'm balancing competing priorities. That's the language I used to justify my actions on my son's last day of first grade. My goals that day were unrealistic. Scrambling, I arranged for a parent of one of my kid's friends to meet him when school released. They would play on the playground until I could get there. He wouldn't even notice my absence with the heightened stimulation from the last day of school, I reasoned.

When I arrived, the schoolyard teemed with wild, exuberant children, embracing the freedom that summer represented. But my son stuck out: He was the only sad kid there. Even now, I see his little face wracked with disappointment, his sweet puppy dog eyes fighting back tears. I had missed the incomparable hoopla known as the last moment of the last day of school. Armed with cameras, all the other parents had shown up to catch their children flying out the school doors. Congratulations! balloons. You made it! cupcakes. I missed the hugging, the screaming hooray-summer-is-here moment.

He's 16 now, but he still remembers that day. When my kid hurts, I hurt myself, too. My absence at the end of the school day didn't match my words at the beginning when I said I'd be waiting for him when school let out and summer began. This experience crystalized for me that punctuality is essentially making good on a promise. I was accountable to my 7-year-old, and it crushed him when another mom instead of his own showed up. My actions had inadvertently communicated that he was less important than my work, when in fact, my noblest work is wrapped up in being his mother.

That day I learned that being on time does more to prove my love for my child than professing it. I could say, I love you a million times, but showing up when I say I will is far more convincing. It is love in action.

After that one major lapse of judgment, it took years of getting it right to make amends. I doubled-down. I made punctuality a priority.

With that memory pulsing through my mind, I raced out the doctor's office and hit the highway toward my son. With a final burst of adrenalin, I hurtled my Jeep into a parking place, cutting the engine just as the bell blared around the school complex. A moment later, my son approached. He shot me a grateful nod and hopped in.

I'm here. I love you. Now, let's go home.