Crafting a 50th grade-school reunion? Elementary.

I can still remember my last day of school in eighth grade at what is now known as Blessed Sacrament Academy, on Euclid Avenue in Cypress Hills, Brooklyn. This would have been in June 1973.

The nuns handed out these small leather-bound books with the school logo and zippers. When you unzipped it, it was full of blank pages. The idea was, since this was our last day together, to get all our friends to sign our books. Even at that age, I knew something was wrong about this.

I had been with my classmates at that point for seven years (I actually attended kindergarten and first grade at another school before my father uplifted us to live near his family). I knew we’d all be going to different high schools, and then on to college.

I remember so clearly thinking: How will we ever keep up with one another? Here we’ve spent all this time together, and now we’re all going our separate ways? It didn’t seem right then and, in retrospect, it really wasn’t.

I then spent four rigorous years at Archbishop Molloy High School in Jamaica, Queens. Then I stumbled around until finally graduating from Pace University, before moving to Albany for my job.

Soon after that, I was married and raising kids. To say I was busy would be putting it mildly. Still, I never forgot my elementary-school friends, and I always wondered what happened to them.

That’s the thing about moving away from where you grew up and went to school. To this day, my wife can go into a store and see someone she went to school with. Many times, she may have not seen them for decades, yet they hit it off in an instant. It’s like they never left.

Because I grew up downstate and moved to the Capital District as an adult, I never have that pleasure. I would so have loved that.

A few years ago, I realized that it would soon be the 50th anniversary of my grade-school class. I got to thinking about some kind of a reunion. So I wrote a letter to the school asking for the 1973 school roster, including current addresses if they had them.

No response. I continued to write letters. Then I started sending in donations.

Finally, the older brother of a girl I went to school with called me (he is a school board member). Tony explained they would be doing either a golf outing or some other kind of school-wide activity, and would be sure to highlight the class of 1973. That was good enough for me so I forgot about all this for a while.

By this time, I’d started to reconnect with my grade-school pals on Facebook. One minute, you haven’t seen or heard from someone for almost 50 years; the next minute, you’re seeing photos of their grandkids graduating from college. Amazing.

I let them know I was working with our old school on a reunion. They were getting excited, which was great. But I had not heard back from the school, and for good reason.

After writing more letters (never underestimate the power of a well-written letter), Tony called me again. He said the school had been dealing with declining enrollment for years, and there was just not the funds or resources to pull off any kind of alumni event. That meant it was time to, as celebrity chef Emeril Lagasse always says, “kick it up a notch!”

I requested help from my classmates on doing our own 50th grade-school reunion. Wouldn’t you know it, the prettiest girl in our class, Francine — the one all the boys, including me, had a huge crush on — wound up being my go-to partner in getting this event going.

Unlike myself who never kept in contact with anyone once eighth grade was over, she had A) stayed living close to “the city,” and B) kept up with many of the girls in our class. Francine was a real help, and to be working so closely with her after all these years was really unbelievable and wonderful.

Here’s the plan we came up with:

— Have a tour of the old school on a Saturday at 3 p.m.;

— Have mass in the church right across the street at 4 p.m.;

— Get together for dinner somewhere at 6 p.m.

Of course, the big problem with this plan was getting into the old school. Fortunately, Tony, the board member who I had been working with, came through for us. He arranged for someone to meet us at “the door” on the date we chose, which turned out to be Saturday, Oct. 21.

I put “the door” in quotes because it wasn’t until I returned there after all these years that I remembered that there are actually separate boys’ and girls’ entrances at Blessed Sacrament School. That’s how long they’ve been around.

On the appointed day, my wife and I drove to Brooklyn. We were greeted at the boys’ entrance by Felix, a church employee, who was very welcoming. Then my classmates started to arrive and, just like that, we were inside halls and classrooms that I hadn’t set foot in for over 50 years.

The little desks, the bathrooms with that industrial-cleaner smell, and the lovely pine-floored gymnasium; it was all there just as I’d remembered it. What a feeling. Plus they now have beautiful outdoor recreation spaces for the kids, with playground equipment and everything. Wish we’d had that!

One of the things I most remember about elementary school was when the school-wide sound system would squeak to life and make the following announcement: “Mr. Peters, please report to Room 201” or some other room.

This meant that someone had either peed their pants or threw up. Our long-suffering janitor, Mr. Peters, was no doubt a saint.

When I mentioned this to my classmates one of them, a lady, said she was the reason for many of those calls. She said at times she got so panicked by something or other that she just couldn’t help it.

If my classmate was that nervous and scared in school 50 years ago, imagine how today’s kids must feel with all the school shootings these days? It hurts to think about it. These poor kids.

After the school tour was over, we went across the street for a Catholic Mass. The kids of the school were all sitting together with their classmates, just like we used to do.

Towards the end of the Mass, the priest asked if anyone from the class of 1973 would like to speak. You could see my classmates’ backs stiffen; public speaking, for many, is that scary. However, I’ve been thriving in Toastmasters for so many years now that I love getting any chance to speak in public, so I got up there, having no idea what I would say.

As I looked out and saw that sea of young faces so full of potential, it was obvious I should talk about the benefits of a Catholic education.

I told the kids that at times they may find wearing uniforms (plaid skirts and white blouses for girls; white shirts, plaid ties, and black pants for boys) to be cumbersome; that they may find constantly being reminded to sit up straight, turn in their assignments, and keep in order to be trying; and that they may find the heavy academic workload to be unbearable at times, just as I and all my classmates did.

But then I told them, if they just kept up with it, I knew that I was looking at the next generation of doctors, engineers, lawyers, and other professionals. I told them to look at my fellow classmates and me as inspiration, because, if we could do it, so could they.

My speech was very well received. When you speak from the heart about truly good things, then truly good things happen.

After the Mass we all went out to dinner at a fine restaurant. Catching up with everyone after so many years was exhilarating. The food and friendship were both terrific.

Everyone said we need to get together again real soon. My plan going forward is to have some kind of a picnic in the summer. Many of my classmates now live on “the island,” so it’ll probably be in Nassau County somewhere.

But no matter where it is, I know we’ll all enjoy each other’s company and just reconnecting after all this time.

Many of my classmates, including my closest friends, could not be located despite scouring social media for hours. Others are no longer with us, which is to be expected of course since we’re all in our sixties now.

I wish I could get a handle on each and every one of us, and I’ll continue to try. But it’s just so great that we have this core group now. Many good times await us, I’m sure.

Putting together a 50th elementary-school reunion was a lot of work, but the results were outstanding. If you still have friends from grade school that you are in contact with, consider yourself lucky. Material things come and go, but long-time friendships are just priceless.