Smartmom was happy to learn that Gap Year University has a “study-abroad” component.

Teen Spirit didn’t exactly go to Europe or South America. He went on a road trip to Texas, which is, in a way, a foreign country.

There were no teachers on this trip. No itineraries. No syllabus of appropriate literature. It was, you could say, an independent project. Life was the teacher, and whatever happened on the way would surely be a life lesson of sorts.

On a rainy Saturday morning in March, Teen Spirit set off with three other friends in a Toyota.

“A Toyota,” Smartmom thought. “Oh, great.”

After days of preparation, Smartmom was stressing. She helped Teen Spirit make a list of what to take. How much money would he need? What was the weather down in Texas? Did he need a sleeping bag? A raincoat? An umbrella, for Buddha’s sake?

About the driving, Smartmom had moments of panic imagining a car accident on the Interstate (the Toyota, remember?). She reminded herself that the driver, a suburban girl, is confident and has many miles under her belt. But she still couldn’t quell the fear that something might go wrong.

And where would they stay? What if they happened upon some weird Bates Motel-type of place or decided to camp out in some scuzzy campground?

It was all possible, but Teen Spirit and his friends were on their own, and there was no way she or any of the parents could micromanage this trip. That was the point.

Smartmom thought back to the trip she took when she was 16. She and two friends biked from North Carolina to the Appalachian Folk Life Festival in West Virginia. Her father almost didn’t let Smartmom go.

“It’s dangerous in the South,” he told Smartmom. “You’ve seen ‘Deliverance.’ ”

Thankfully, after much pleading, he let her go. Smartmom still can’t believe it. It really was a potentially dangerous trip: three 16-year-old girls alone on a bike trip, staying at campgrounds and weird motels. At one place, the woman at the desk asked if they were runaways.

But it was the adventure of a lifetime, which built self-confidence and many memories. Smartmom is grateful to this day that the late great Groovy Grandpa said yes.

That’s why Smartmom was open to Teen Spirit’s request to go down to Austin in a car. She knew it would be a great adventure and something he’d remember for the rest of his life.

The night Teen Spirit left, it was raining in Park Slope and Smartmom had a panic attack while watching “The Crucible” at the Old Stone House.

“What if they’ve been in a car accident? What if they’re dead by the side of some road?” she thought during the play’s witch trial scene. Her heart ached for her son. She should never have let him go away.

As soon as she got out of the show, Smartmom called Teen Spirit. Her panic melted away when she heard his voice on the phone.

“We’re in Kentucky,” he said cheerfully. “We’ll be stopping for the night in an hour or so.”

Smartmom tried not to think too much about Teen Spirit in the coming days. She did feel a pang when she came across his skinny jeans with the huge holes in the backside lying in the hallway.

During the first week of Teen Spirit’s trip, Hepcat got a text message from his boy. He called Smartmom excitedly.

“He wrote: ‘Been to Sun Records, On my way to Graceland. Life is good.’ ” Hepcat told Smartmom.

“He didn’t text me,” she told him.

Still, she was delighted with his message. Life really is good when you’re 18 and on the road. A few days later, Smartmom called Teen Spirit’s cellphone.

“We’re in Austin,” he told her. “And we’re not going to that music festival in Monterrey, Mexico. There’s a drug war and it doesn’t sound like a good idea.”

Smartmom was relieved beyond words. The group planned to go to MtyMx a music festival on the heels of SXSW, organized by Todd P, an all-ages event organizer in Brooklyn. They were going to take a six-hour bus ride from Austin to Monterrey, Mexico. But in Austin, they’d heard reports about drug cartels and the violence.

Smartmom felt relief. She was awed by the fact that Teen Spirit and his group had made the decision to avoid what was a potentially dangerous situation.

A few days later when Teen Spirit got back from his trip, Smartmom was away at a writers conference in Delaware.

“The Prodigal Son returned at three in the morning,” Hepcat told Smartmom the next morning.

Smartmom was happy. Her son was back from his trip of a lifetime, yet another feature of his year at Gap Year University. They had trusted him and he rewarded their trust with good decision-making and a really good experience.

Now the big question: How many credits did he get?