Isla Mujeres -- the "Island of Women" -- was named by Spanish conquerors who in 1517 discovered clay female figurines (replicas: 200 pesos) dotting the picturesque land. With the pounding surf on one side (jet skis: 450 pesos/hour) and a tranquil reef on the other (Sol with lime: 15 pesos), it's just a five-mile ferry ride (free with all-inclusive hotel package) from the public port at Cancun.

Standing on the dock, we awaited our boat to the island, soaking up the perfect Mexican sun and breathing the salty ocean air. I was nearly transported back in time. Except that Rick James' "Superfreak" was blaring over the loud speaker from Fat Tuesday's. I couldn't help but point out to my fellow travelers that mariachi music would have provided a much more suitable soundtrack to the scene.

I wasn't exactly ruining a perfect Mexico moment. The bungee jumping attraction (350 pesos) already did that.

Real life does not come with the perfect soundtrack, precise lighting, or free passes. No, unfortunately, the real world is handicapped by reality. And by "reality," I mean that there's a cash register and neon signs with admission charges standing between you and the ancient Mayan ruins.

I'm reminded of the credit card commercial where people -- free from the humdrum constraints of their everyday lives -- create priceless memories together. And it's true: The most meaningful things in life are free. It's just setting the stage that'll set you back a grand or more.

Which brings me back to Isla Mujeres. Otherwise known as "Temptation Island," if you're counting your pesos.

The toll of travel
My trip to Mexico was a well-planned affair. A good friend was getting married on the Isla, and she and her groom picked a small resort on the tip of the island for the festivities. All the guests could stay at the same place, and if you chose the all-inclusive package, meals, beverages, and airport transportation were included.

I don't take true vacations often, and I had the money in the bank to cover my expenses two times over. Reality wasn't going to ruin my good time. I was in Mexico! In February! The pina coladas were already on my Motley Fool Visa!

Still, I write about money for a living; I think about money every day. So when the sand in my tennis shoes became distracting, I winced as I shelled out for flip-flops (120 pesos) and felt a few pangs of guilt buying a beach wrap (180 pesos) and then a prettier beach wrap (200 pesos) the next day. I marveled at my fellow travelers who discovered how to save 400 pesos on golf cart rentals by venturing just a few hundred yards across the bridge into town.

Seeing the sites means you aren't necessarily around to snack from the free buffet at the hotel when hunger strikes. Trust me, you do not want to pass up the guacamole the locals make -- with the perfect combination of lime and cilantro -- just because it's not part of the all-inclusive package. And nothing beats Sol and a sliced lime for washing it all down.

It wasn't long before I stopped counting my pesos. One day into my trip, I knew that the money in my wallet was earmarked for my good time. Even three days after the trip, the unplanned expenses were a distant memory. And now, just three weeks later with credit card statement in hand, I'm not stewing over the $12 flip-flops that I could have picked up at Target (NYSE:TGT) for $5 before I departed.

While I would never counsel others to spend willy-nilly on a trip, there's nothing more refreshing and freeing than not having to worry about money. The only way to do that is to heed those jolting neon dollar signs in your mind and plan your budget. It doesn't take much longer than packing to come up with a simple estimate of what you might spend. Going one step further by setting aside money in a separate interest-bearing account will free you even more.

Most "priceless" memories carry a price tag. Knowing what they cost beforehand makes the unattractive realities fade and the best moments live long in your memory.

The best things in life are free
The sand has been washed from my swimsuit and the flip-flops are packed away until summertime returns to Washington, D.C. While my Mexican adventure is still fresh, it's already clear what moments are destined to become priceless memories.

On my first sunny day, there we "stole" an afternoon on the private dock at the exclusive hotel where the bride and groom planned to honeymoon. Since only one guest was checked in at the time, we figured no one would notice if we laid our beach towels on the teak deck chairs down the hill. A friendly waiter kept us happy with big bowls of guacamole, chips, and cervezas in chilled beer mugs.

The next day the winds became dramatic and, though the weather looked threatening, the bride insisted that the ceremony take place outdoors as planned. Halfway through the ceremony, the groom invited all of the guests inside of the gazebo to huddle around the happy couple as they exchanged vows. For more comic relief, the mariachi band, unclear about Jewish customs, burst into song every time someone on the altar took a sip of wine. (By the way, the international symbol for "cut the music" looks similar to the international symbol for "I am going to slit your throat." The mariachi band avoided me the rest of the evening.)

During the reception, we all were treated with what has to be a musical first. I saw one of the groom's friends talking with the mariachi band, which had been joined by a few brass players. Moments later, they burst out with the wedding/bar mitzvah classic "Hava Nagila."

The turquoise statue ($20) and white maracas ($10) on my mantle are tangible reminders of my trip to Isla Mujeres. I couldn't help but chuckle when I saw the same maracas for sale at a store two blocks from my house. I swear I can feel the salty air on the gourds I carried back in my suitcase.

Dayana Yochim is the author of The Motley Fool's Guide to Couples & Cash. The Motley Fool is investors writing for investors.