(Annotations by Danna, the granddaughter, are in italics.—Ed)

I never got to travel out of the country until I was well into my 20s. In contrast, my kids started flying across oceans and continents as early as 5.

The twins, my youngest, were still in nursery school when I took my extended family of eight—the whole kit and caboodle—on an unforgettable adventure through California and Nevada in 1999. I had saved for that trip for three years and was in debt for another three years. It was all worth it.

I have always believed that travel was part of my children’s education. And they never stopped traveling since—with family, with friends, or by themselves. Now it was time for the next generation to savor the same experience.

Last April, this baby boomer embarked on a whole new adventure, this time with an alien from Generation Z, my teenage granddaughter. And oh, what an adventure it was—a monthlong roller-coaster ride from sea to shining sea, from the Big Apple to California, across generations on an American experience my own millennial children neither enjoyed nor endured.

(My grandfather—I call him Papa— is the weirdest and oldest man I know. I mean, what kind of person solves crosswords, listens to Beethoven and watches “Jeopardy”—all at the same time? He also tells the worst Dad jokes, eats the yuckiest food, and does the craziest things. And you should hear him snore.

He calls himself a marathon runner and a triathlete, but most of his races are all about making the time cutoff and not finishing last. Friends call him an Ironman, but he now thinks he’s Superman. He’s mixing up his superheroes. Now he thinks he can run the Boston Marathon. But I just played along with the idea because I got to travel with him to Boston and beyond.)

It started with a 15-hour flight, over the North Pole aboard Philippine Airlines’ nonstop haul from Manila to New York. Danna, who is 15, never knew what it was like to travel economy that long, so she had the impression that flying business was the only way to go. She wasn’t as impressed as I was by the comfort of flying PAL non- stop to New York.

My main destination was Boston, where I was to run the marathon of my dreams, but she didn’t really care much about the marathon or the history of that place. She did look forward to visiting the places she only heard about—the Statue of Liberty and the Empire State Building in New York, the Bean at the Millennium Park in Chicago, the bright lights of Las Vegas, and of course, the Santa Monica Pier, Disneyland and Universal Studios in Los Angeles. And the best fast-food joints from coast to coast from a list she had Googled.

In New York, we were joined by my eldest son JB and his girlfriend Jace as we did all the touristy stuff. But the highlight of Danna’s visit was not Central Park, the Metropolitan Museum, Times Square or the Statue of Liberty. It was Chipotle, the popular Mexican fast-food, on the ground floor of the Empire State Building. My cousins, the Chavezes of Queens, were amused as they sent us off to Boston.

(Boston was ho-hum. It was cold and wet and there was nothing there for me except Chipotle delivery and Walmart next door. The Sunday before the Boston Marathon, Papa rested in front of the TV, watching Tiger Woods win the Masters. Holed up in the hotel room with an old grumpy man the whole gloomy day, I thanked God for free hotel Wi-Fi.

While waiting for Papa to finish the Boston Marathon, I joined my Ninong JB and Jace on a visit to Boston’s historic Freedom Trail.

At the marathon finish line, hours after most everyone else had crossed it and only a few minutes before they closed it, I saw Papa shuffle in with his hard-earned medal, ecstatic as if he had won the race. He dropped to one knee. I didn’t know if he was praying or was just dizzy, but a medic put him on a wheelchair and wheeled him into the medical tent.

After a few minutes of waiting in the cold, we saw him emerge from the medical tent—the doctors had dismissed him with a bag of salty potato chips to remedy a mild case of dehydration.

It was such a funny image: a veteran marathoner and Ironman triathlete being taken like a helpless and feeble old man to the medical tent and emerging from it grinning sheepishly like a little boy coming out of the dentist’s clinic with a lollipop. It’s going to be a funny story to tell back home.)

My whole body was sore on the drive back to New York the next morning, but it was Danna who suffered the “post-marathon blah,” that feeling of emptiness and depression usually suffered by finishers the day after the marathon.

JB and Jace stayed behind in New York and left me at the mercy of this teenage terrorist as she hijacked me to our next stop: Chicago. JFK and O’Hare are two of the busiest and biggest airports in the US, yet Danna, a first-time traveler here, seemed to know her way around.

She guided me through the terminals and, within an hour after landing, led me to breakfast at the Burger King joint she found in Google Maps on Dempster Street, in the suburban Chicago neighborhood of Morton Grove. The place brought back memories of my late mother. This was where she used to do a lot of shopping.

Shopping and family reunions have made Chicago my favorite US city. On top of this, Danna had an encounter with Sue, the T-Rex, at the Field Museum of Natural History; agonized over the unnamed Picasso structure in Daley Plaza; and had fun with the Anish Kapoor sculpture nicknamed “The Bean” at the Millennium Park.

She had her eyes on Six Flags Great America, but no one was brave enough to go with her on the scariest roller-coaster rides in the state, so she settled for the scary movie “Us” with cousin Isabella. Danna sat on the edge of her seat throughout the horror thriller, but only because there only three of us in the otherwise empty theater. A “private screening” can be very scary.

Downtown on Michigan Avenue, she ordered a chicken sandwich in the best burger joint in the east; and in suburban Hoffmann Estates, she shunned crabs and lobsters in my favorite crabs and lobsters buffet restaurant.

Teenagers are such strange creatures—obstinate, inscrutable and unpredictable. I have raised five of these aliens and I thought I’ve known them well. But I have to unlearn what I’ve learned from them because now I’m traveling with one from a different civilization.

(I don’t get it that Papa insisted on having me eat a burger when I was craving for a chicken sandwich. He also forced me to line up for a crabs and lobsters when there were so many other choices in the buffet. Old folks are such strange creatures—pigheaded, difficult, but so predictable. I can’t imagine how my dad and his siblings survived their teens. Dad is cool but Papa is so not cool).

The bright lights of Las Vegas beckoned next, but Sin City offered little for a teenager like Danna. And it was too hot and too crowded for a stroll along the Strip.

While the sinners sinned, the strippers stripped and the gamblers gambled, she went through the motion of enjoying the zipline at the Freemont Experience, the dancing fountain of Bellagio and a drive to Hoover Dam, with a brief stopover in Henderson to visit an old classmate.

The highlight of the Vegas stop for both of us was the Cirque du Soleil’s “Love,” a theatrical extravaganza of the songs of the Beatles, the point where the musical interest of three generations—this baby boomer, my millennial son Martin and his Gen Z daughter—had come together, so to speak. Music has a way of bridging gaping chasms between generations and offering a point of convergence where strife and discord roil the harmony of life.

On this high musical note and to an endless stream of Beatles sounds, we drove the long (and winding?) road to Los Angeles, where we were hosted by relatives (the Tuanos of Norco) and friends (the Sambilays of Sylmar).

(I never imagined that traveling alone for hours with my grandfather would be so boring. But I played along as if I was enjoying this thing to keep him happy. And I kept him awake on the road by playing his favorite Beatles songs. Ugh! Why couldn’t we just take turns playing our own music? This long drive through the desert bored me.)

Disneyland in Anaheim had grown much bigger and more crowded and offered nothing new to Danna, who had visited the Hong Kong and Tokyo Disneyland.

On top of that, the morning rain and the long queues took up most of our time (it took her half of the day to go on Space Mountain twice). The Santa Monica Pier and its kiddie rides gave her more fun and excitement per square foot per minute.

But at Universal Studios, Danna savored every ride and attraction and she went back again and again. The tram tour of the back lot and movie sets of Universal Studios is the only one of its kind.

Danna had her heart racing and her hair raising in a car chase with the “Fast and Furious” crew; was stunned by “Jaws,” cowered in the middle of King Kong’s epic 360-degree 3D battle with a gigantic dinosaur.

She had a taste of the wrath of Mother Nature when she was caught under a collapsing subway station during an 8.3 magnitude earthquake and was almost swamped by a rumbling flash flood during a storm.

The ballyhooed mega attraction “Jurassic World” still had to open for the summer, but “Harry Potter’s Wizarding World” was huge. The attraction was said to be a faithful recreation of “the visual landscape of the fiction and films.”

“From its snow-capped roofs and cobblestone streets to the historic British sensibilities that characterize the whimsical look and feel of the land, ‘The Wizarding World of Harry Potter’ transports guests of all ages to the very places they read about in the stories or watched on the silver screen,” says the publicity material sent by Athenia Veliz-Dunn, Universal’s international publicity manager.

It was a magical moment for Danna at the Hogwarts Castle. Again and again, she hopped on to Universal Hollywood’s first outdoor roller coaster, the “Flight of the Hippogriff.”

After her second trip on the Hogwarts Castle’s signature ride, “Harry Potter and the Forbidden Journey,” the crew put her on the next turn without having to fall in line. The ride was a high-speed adventure with Harry Potter through the passageways and corridors inside and high above Hogwarts Castle. Danna washed the exhilaration down with the famous Butterbeer (it’s nonalcoholic, Papa) at the Hog’s Head pub.

It was a fitting climax, the exclamation point, to a month-long journey with my granddaughter. We were together 24/7 for a month. It was a learning experience that filled us both with memories to last a lifetime.

It brought out the child in me, and the adult in her. It changed my view of life, of the world, and of teenagers, my granddaughter in particular.

In my 60s, I learned another life lesson: Traveling with one is the key to unlocking the complex mind of a teenager.

(Wow! What a long trip it has been. I learned more about my Papa in one month than I did in 15 years. But mostly, I learned so much about myself; I can’t believe I could have fun in my Papa’s company. I now know that traveling with one is the key to unlocking the complicated mind of an old man. And I love this old man.

On the flight back to Manila, I gave Papa a hug and a review of the things I learned that were important to me. Carl’s Jr. is a better burger than In ’N’ Out, Five Guys or Burger King; Shake Shack also serves good chicken sandwich. Chipotle is great, but no fast-food chain beats Panda Express. And, sorry, Disneyland, Universal Studios is now my “happiest place on earth.”)—CONTRIBUTED