Give it up. The snorkeling mask isn’t going to fit over your glasses, so stop trying to adjust the straps, you idiot. Enjoy the moment. There are turtles to see.

The idiot is me—I’ve somehow found myself swimming off the shores of Culebra, a tiny island of Puerto Rico. Vacations are as mysterious to me as weekends are to the Dowager Countess of Grantham. What are they? Who engages in such frivolity? Most important, how do they make everyone so happy? Armed with four days of free time, I’ve decided to find out. I start by holding my glasses in my hand instead of fussing with the mask.

To some people a trip to the Caribbean would be just another weekend, a fast getaway from the grind. (How quick? JFK to SJU airport is three hours and 42 minutes.) I’m under no delusions about this being the most foreign place in the world—it’s probably one of the least, actually. You don’t need a passport to travel here from the U.S., and the biggest cultural barrier is distinguishing oeste (west) from este (east), which isn’t even essential unless you’re driving. But this doesn’t really matter.

During our “aquafari” day on the beach, my friend Adam and I learn how to kayak with our incredibly toned and tan guides Edwin, Brian, and Iris. The cute and dreadlocked Edwin shares with us his unabashed love of turtles—later, in the water, he points out Lola the sea turtle: “She doesn’t like me very much”—and recommends that if you love the water, Culebra is the place to be.

It’s no lie. We spend two hours on the intensely sunny Flamenco Beach, where the water tastes perfectly salted and the sand’s so fine I’ll find it in my roots five days later. Besides soaking up the sun and choosing a food stand for lunch, there’s not much to do in Culebra—and that’s the point. For three bucks, a man wearing a Scarface T-shirt will pluck a coconut from a basket and hack at it with his knife until a hole appears. He gives it to me with a straw, coconut water straight from the source. Take that, Zico.

We’re driven to Culebra’s Tamarindo Beach to kayak. After a three-quarter-mile rowing session, we jump out to observe coral reefs. Many of the coral types are endangered, and our guides point out large swaths of coral deliberately placed around man-made wire structures to encourage growth. We put on flippers to snorkel and recognize turtles and fish from Finding Nemo. We hold a starfish and avoid urchins.

Later that night, my skin is burned and so pink, it has its own pulse. If this is vacation, I’m beginning to like it.

Weird things can happen when you shake up your routine. Weird things, but also great and illuminating and calming and sometimes upsetting things. For instance, only on vacation can you open up a hotel-room phone book and find a note claiming to be from a ghost named Samantha. This ghost guest writes in Spanish and tells us that she haunts our eighth-floor, ocean-view room. (We never see her.) Only on vacation can a man at the blackjack table rub his generous American belly and call himself “El Gordo,” then offer the dealer a soggy $20 bill, and get the response, “This from pool or ocean?”

Only on vacation can you become a strange, unrecognizable version of yourself. Usually I have a strong aversion to asking waiters what to choose on a menu. In Puerto Rico I become completely susceptible to the suggestions of locals. Oh, you like the shrimp mofongo? I’m sure I will too. And boy, does Ropa Vieja deliver. For the uninitiated, mofongo is a Puerto Rican dish made of fried green plantains crafted into a big delicious tower—think Close Encounters of the Third Kind with plantains in lieu of mashed potatoes—and filled with seafood, vegetables, or beef. Yelp claims there are seven restaurants around Manhattan that can satisfy a mofongo craving, including the delightfully named La Casa del Mofongo, but it’ll be a miracle if any of them come close to the real thing.

Besides mofongo and tostones (twice-fried plantains), there’s meat, meat, and more meat on every menu. Within four days, I inhale churrasco at Pamela’s, a lovely and secluded beachside restaurant that’s supposedly a favorite of Benicio Del Toro’s, chicken and rice, fried pork chops from a hole-in-the-wall place in Old San Juan, and chicken pinchos on Flamenco Beach. No guilt here. I am, after all, eating for two. (Adam is a vegetarian.) We also make time to hit up San Juan’s only casual vegan place, Pure and Natural, for fish tacos, a “power plate” of brown rice and vegetables, and papaya juice. For a brief moment, vacation makes me consider swearing off meat forever. Then I hear JFK’s Terminal 4 is getting a Shake Shack and desperately wonder if it will be serving burgers by the time we return home. (Alas, no. It will open in May.)

One of the must-visits on a trip to Puerto Rico is Old San Juan, blocks and blocks of which are filled with grand Spanish colonial architecture. It’s a short bus ride from the tourist-heavy Condado area, or a decently long walk. It’s 78 degrees out (and snowing in New York), so walking wins.

After choosing which streets to go down on a whim, we come across Ole, a store specializing in Panama hats located on Calle Fortaleza. A giant sign on the door tells us it was one of the recommendations in a recent New York Times article by Charles Isherwood. It’s as narrow as a subway car and packed with posters, sketches, and shoes. The owner stoops to look at my blue and white striped espadrilles. “Are those Toms?” “No, Soludos,” I say, and look down. They’re dingy as hell. He’s selling a nearly identical pair (at half the price I paid for mine) made in Chile. Of course I buy them.

We make our way to Castillo San Felipe del Morro, a 16th-century fortress on the westernmost tip of the island. It’s forbidding, if not for the tiny black cat guarding the entrance like a feline sentry. Built by the Spanish to defend San Juan from invasions, it’s now quiet save for the tourists and undeniably gorgeous. If some photo genius could recreate “El Morro at Dusk,” it would be the most popular Instagram filter ever.

Our walk back into the city leads us to El Batey, immediately deemed “best dive bar in the world.” Dark and graffitied from ceiling to floor, it looks like a jail emptied of its prisoners. Lampshades over the bar are clipped with business cards. The Puerto Rican beer Medalla is cold and cheap, Elton John’s “Rocket Man” plays on the jukebox (yes, really) and the pool table is free of players, so we take turns shooting with the shorter cue—the walls are so close to the table that some angles are impossible.

We start the 40-minute walk back to our hotel (it’s funny that we don’t mind playing hand after hand of blackjack, but refuse to commit to a $10 cab ride). On the way, a man across the street starts shouting at us, asking if we speak English. He says he and his 78-year-old father were roughed up and robbed in a bad neighborhood near El Morro that night. The police helped them, but now he needs $8 for a cab ride from the hospital. I’ve been asked for money six ways to Sunday in New York, but this doesn’t look like the kind of guy who’s ever begged for anything in his life. After Adam gives him some cash, he tells us his email address and says that if he doesn’t hear from us about repayment, he’ll make a donation to his church in Milwaukee. We decide a taxi is a necessity after all and go to shake off the unnerving interaction the best way we know how: gambling.

Each den of sin has its selling points, but Puerto Rican casinos make good with $5 minimums at the blackjack tables. At that rate, even a novice can play for hours. They’re not as glitzy as Las Vegas, but have their own charms. Luis and Ricardo are our dealers for the evening and alternate turns so quickly and seamlessly that we barely notice. It takes about three minutes to feel easy, comfortable, and in control of the hands you’re dealt.

After an hour or two, a Puerto Rican guy in a red and white striped polo sits down at the table but doesn’t acknowledge anyone. He has a proper glass filled to spill with something resembling whisky or Scotch. I calculate how often and how much I’d have to gamble to get my whisky served in a glass instead of this plastic thimble sitting in front of me.

Later, in the middle of a hot streak, the polo guy starts calling me “Miss 21, Miss Blackjack.” After winning back the previous night’s losses, we quit. Even the dealer’s surprised to see us go. But sometimes it’s best to just walk away. Besides, there’s a Denny’s across the street, and there’s no shame in eating blueberry pancakes after midnight. Or gambling for three hours a day. Or napping in the sun. Or drinking at noon. Wait a second ... I think I’ve found it! This just might be what they call ... a vacation.