It was March 22, just 10 days after he turned 18, that my son became a man.

I was doing some late-afternoon, after-work grocery shopping when he called me. You know that kind of grocery run, when you've stayed too long at work and your brain is scanning the aisles for dinner inspiration, something you can make quickly so it doesn’t look like you put off dinner planning until almost literally the last minute.

"Mom," Ryan says. "You know how I got my ASVAB score the other night?"

"Mm-hmm," I said into the phone on my shoulder, my gaze swiveling across the shredded cheese.

"I decided to go see Sergeant Hall after school and see what jobs are available to me with that score."

OK...that could go with the tortillas I have at home. But I'll need chicken breasts.

"So there was a satellite communications job with one opening. It comes with a $25,000 signing bonus and the leave date isn't until August 8."

Wonder if those peppers in the fridge are still any good?

"So I took it."

Wait...what?

And just like that, my sweet little boy, the one who weighed only 5.5 pounds when he kicked his way into the world about five weeks early, all scrawny arms and legs like the baby bird we called him, made his first adult decision. And boy was it a doozy.

Never mind that he towers a good nine inches over me now and has put quite a bit of muscle on his slender frame. In my head, he was that preschooler slipping his hand into mine and randomly telling me he loves me.

It wasn't completely out of the blue. I mean, we'd had long talks with the Army recruiter since November. We don't have much military history in our family, and we didn't know what we didn't know.

Everything about the military is a completely different language and culture.

Ryan began talking earlier in the fall about joining the Army, as his friends were touring college campuses and picking their majors. Highly dubious, I dragged him through the same college-selection process that we'd been through with his two older sisters; this the third time around it was almost old hat.

ACT tests, Common App, scholarship essays, even FAFSA...that made sense.

When I demanded he at least look at a couple of schools, he picked a small, private, out-of-state college with a picturesque campus, stone buildings, and an annual tuition bill twice my part-time church employee salary.

He reluctantly toured a medium-sized state school on a flat, bland campus—but I suspect that was as much about getting a day off school as anything. He applied for and was accepted to both places, but there wasn't much financial help available for a kid with near-gifted intelligence whose GPA hovered at a C-average (even with two older sisters in college).

After a while, I'd conceded the military might not be a bad choice. The perks are pretty sweet, considering the Army will pay every bill associated with the college classes he takes while he's in, and the G.I. Bill will help him later.

He'll learn a marketable skill that will transfer to the civilian life, probably with a better salary than his parents—combined. It will give him direction, discipline, and structure that will do him some good, especially since he didn't have a better idea.

I've tried not to think of the considerable risk.

And truth be told, he's the middle child of five. He's always needed to chart his own course. It didn't sit well with us when he was nine...or 10...or 13…you get the idea.

For as sweet as he was when he was little, he found plenty of ways to butt heads with us when we tried to steer him our way. I suspect he was tired of living in his high-achieving sisters’ shadows.

He needed to forge a new path.

Allowing that the military might be a legitimate option for him, I had pressed him to contact the other branches, so he could make an informed decision. But there again, he did it his way. He liked what he heard from the Army, and that was that.

As I stood there in the Giant Eagle dairy section that afternoon, reaching vaguely for a nearby milk jug for support, I tried to gather my senses and fight back the tears welling from somewhere deep within.

I listened again, more intently, to what he was telling me and slowly absorbed that he had already signed on the dotted line. He would leave in a few days for additional testing and a swearing-in ceremony.

It was real.

He tried to explain what "satellite communications" even meant, but my only points of reference were late-night episodes of NCIS—and that's the Navy anyway—and M.A.S.H.

"It's nowhere near the front lines," he said, anticipating my racing thoughts. "Mom, it's basically a desk job."

Except I don't know very many desk jobs where you have to/get to (depending on your perspective) jump out of an airplane. (He's in the Army's Airborne Division.)

I told him I was proud of him and that it sounded like he had made a smart choice. I fumbled through the rest of the store and checkout, and once in the car, the tears surfaced.

Not because I disagreed with his decision. I was disappointed, but not shocked, that he made it without either of his parents at his side—but that’s part of growing up, and honestly, it was about time I got on board.

No, I was proud. For as many personal benefits there are to enlisting, Ryan is excited to offer himself in the service of our country. He wants to help. We raised him to put others first, and he has a servant’s heart that does genuinely swell with patriotism. He would give the last dollar in his wallet to help someone else. I know God has a plan for him, and I’m not too worried about what I can’t control. I don’t know where this path leads, but I trust that all will be well.

We’re honored to be joining the Armed Forces family and have experienced its proverbial embrace when even complete strangers learn he’s enlisted. There’s usually a pause and a handshake, with some expression of gratitude for his service. Veterans nod in respect, and if asked, will offer a word of advice to a) keep his mouth shut, b) don’t volunteer for anything, and c) enjoy every minute. I suspect that all will make more sense once he’s in the thick of it.

I just don’t want him to get hurt.

That night, as I mulled his announcement, my mind kept flashing back to when he was 4 years old, and he mustered more bravery than his older sisters, squared his jaw and dared to ride down the 70-foot, vertical drop, ice-covered toboggan chutes with his dad. At the bottom, we discovered his pants were wet.

But he said he would do it, and he did.

Even then, a man of his word.

This post is part of Spring.St's In Service series. We're looking at military life and the hard-working families that serve the United States. You can read more here.