Every day, I hear the same thing from parents of grown children.

“Enjoy it while you can, it goes so fast.”

With a 3-year old boy, Elias, who consistently wakes up in the middle of the night “needing sumfin” and a 6-year-old girl, Willa, who also wakes up frequently, saying “I just can’t get back to sleep,” a house so colossally messy I tell my wife it looks like crazy people live here, and extreme time poverty that makes taking a shower difficult (let alone getting to work on time or weeding the front yard), I find this advice baffling.

How can you enjoy something when you can barely function — especially when the thing you are supposed to enjoy is the cause of your dysfunction?

When I came home on a windy day recently, a day when a Porto-potty had blown over in the park, Elias asked me if I had blown away. At work that day, after a two-week vacation and an exceptionally sleepless night, I had forgotten the combination to the door and my intern’s name, and had entirely missed an important meeting in a room adjacent to my office. “No,” I said, “I’m here, I’m O.K.” — while thinking maybe I actually had blown away.

Of course, children are gems that decorate and inform our lives with running, miraculous commentary, and there’s an unending supply. Staying at a lousy Comfort Inn, Willa says: “And we get to stay in these incredibly fancy hotels!” Elias, on a road trip: “When do we get here?” (A metaquestion I ask myself, in other forms, all the time.) On the counter in the morning, a note from Willa: “peder pan will you pleys leev mee a mesij.” Elias: “A song is not a thing, it is a sound.”

But the reality is that one is often too harried or tired or overwhelmed to fully appreciate it all. So sadly, disengagement sometimes becomes the Holy Grail of parenting, like when a child gets in a rhythm and plays alone. When they’re in the zone, it can go on for hours, and it’s a miraculous deliverance, a time when one can clear the detritus from the kitchen floor and deal with the piles of papers on every surface. When it happens, it’s crucial not to break the spell.

Elias has started “playing cars” on the living room rug, moving two Jeeps around and narrating the story, always a journey. “OK, I’ll see you when we get there. Do we have our things? OK, let’s go.” To me, who in dazed exhaustion finds meaning and metaphor in everything, Elias is narrating the only human story, a quest for something as yet undefined, and he will continue to do so, if he is lucky, for four score years or more.

Recently, with a second to spare from work and the bathroom remodel, and temporarily ignoring the sink full of dishes, I sat down on the rug and started playing cars with Elias. It wasn’t absent minded on my part; I did it consciously, trying to heed the advice: “Enjoy it while you can.”

“OK, get in the car Dada. You are with Willa and I am with Momma.” (I like that Elias speaks in formal English, without contractions.) I ask: “Where are we going?”

“Maryland.”

Moving the cars around on the rug, I realized what I had done: Now, playing cars is a two-person activity, no longer a break for me. Now, I’ve blown my chance to get anything done around the house. “All for the cause,” I think. And we pretend that the patterns are roads.

Funny that he should choose Maryland, I think, pushing my jeep and mumbling “babababroom, broom, broom, broom!” Baltimore was where I met my wife. We were at a wedding of a friend, and had breakfast at the Nifty Fifties Diner, the motto for which was “Love at First Bite.” As my wife recalls, I took her leftover omelet, wrapped it in a napkin, and put it in my pocket. Unbelievable. How could any person have been so cheap?

It reminded me: I used to cook at the Charburger, and a waitress came in one day from the laundromat. She had six pair of underwear someone had left. They were probably my size. Did I want them? Yes, I did, and I wore them for years. Was I really that person?

Elias shakes me from my reverie: “Dada! Dada! Listen to me! You have to come with me.” Crawling behind his jeep, he looks up and into my eyes quizzically, as if to say: “Dude, get it together!” Grasping for the present, I had found myself touching the unfathomable past.

He says: “We need to get some gas! You are driving Willa and I am driving Mama. We are going to Maryland.”

I am happy to go.