The days are running by now, ridiculously running, like Phoebe in Central Park. They are out of control. Unstoppable.

The graduation announcements are out. The party planned. The prom is over. Finals start this week. His last high school concert, ever, was Sunday night. Ev-er.

There’s this [see photo], which has been hanging in Luke’s closet for a couple weeks. He graduates in less than three weeks.

I mean, holy moly. We spent 18 years planning for this and, all the damn sudden, it’s on us. In some ways, it’s already passed us by.

The other night, when a buddy of his scored a ticket to the Hawks’ playoff game, Luke drove down to the MARTA station, got on the train headed south, switched trains to go over to Philips Arena, snarfed down a burrito, met his buddy, went to the game, stayed for the whole dang thing, got back on MARTA, switched trains twice to get to his car and drove home after midnight.

He’s 18. He should be able to do that, right?

But, man. Wasn’t he just holding his mom’s hand to cross the street, like, yesterday?

Mary Jo and I are at once both melancholy and flabbergasted at the speed of this thing. We worked to get here, to get Luke in this position. And now that it’s a real, palpable thing, you just want to say, “Whoa, whoa, whoa, whooooa now. What’s the hurry?”

Sunday night, we’re standing around in the lobby at his high school, waiting for him to emerge from the band room after that last concert. While we’re waiting, we’re greeting parents who we’ve come to know over the past several years, and we’re all shaking our heads.

Some, with multiple kids, handle it a little better. Most put on brave faces. And, for sure, brave is something Mary Jo and I do, too. I mean, this kid — our kid, a cereal-chomping, sock-strewing physical chunk of us, of our lives — has a full, wonderful, exciting life in front of him. College, with all its possibilities, is just months away.

But … wow. No more arguments about doing homework or throwing clean clothes on top of dirty clothes on top of what we can only assume is his bedroom floor? (We haven’t seen it in months.) No more pushing him out the door to go to the gym or pleading with him to answer an email? No more yelling up to him in his room to come to dinner? No more begging him to tell us something once in a while? Just once, even?

No more laughing as he wrestles with the dog, or when he says some stupid high-school-hip thing that inevitably makes me giggle? (I think he’s funny … but I’m too easy, probably.)

No more daily hugs for his mom, either the real ones when he’s tired or the fake ones when he’s trying to get something? No more messing up the kitchen with 10 p.m. fridge raids?

I’m pumped for him. To be 18 again … amIright? And, as I’ve said before, I’m psyched for what lies ahead for Mary Jo and I. It’s an exciting time in the household. Yes it is.

But, man. It is just stunning. These days, his last as a high school kid, each carry a stinging note of finality, that heavy tinge of melancholy and a real longing to just slow down, for a moment.

Let’s read a little Harry Potter, for god’s sake. Let’s watch some Psych. Let’s take another trip to Cincinnati to see your cousins, or go on another adventure to California. Let’s get down on the floor to play Legos with your Nonna. Let’s dig a hole at the beach. Let’s go see family in Italy. Let’s see Times Square again.

Let’s sit around the dinner table and talk about the day, or lie around the living room with the dog. Let me put you on my shoulders again. Let mom kiss that boo-boo.

Heck, let’s argue a little about those dirty clothes on the floor, or that days-old $7 half-filled Starbucks cup smelling up the car.

Let’s just hold on for one second, all right? One second. Can we? Please?