The night I turned 21, I swaggered into a college watering hole in Camden, New Jersey. No longer would I flash a doctored Connecticut license and pose as a haggard 42-year-old Stonington man named Kurt. At the stroke of midnight, I could buy a beer legally.

The barkeep slid my license back. “I can’t serve you,” he said. He thought my real ID was fake. Who, after all, has February 29 for their birthday? I protested, but it was no use. “Plus,” he said. “It’s February 28. Come back tomorrow.”

Here’s the thing about birthdays: They happen each year. That’s a birthday’s job: You turn a year older, whether you blow out the candles on the cake or not.

Unless you don’t have a birthday. For 187,000 of us in the U.S., that’s what happens three-quarters of the time. We leaplings, as we’re called, have defied 1-in-1,461 odds to have our birthdays fall on February 29. Some would figure that makes us special. It depends on how you look at it. News reports in secondary markets sometimes feature leap-day births or an octogenarian leaper’s 20th. Back in 2008, Martha Stewart hosted 200 leapers on her show. They wore frog-mouth name tags (frogs leap, get it?). “I think you’re all so lucky!” Stewart said, sort of sincerely. She gave them each state-of-the-art digital picture frames.

Leapsters keep two sets of ages, annual and quadrennial. We mark time between real birthdays in fourths and halves. Leap-year days serve a purpose, as we know: The extra day tacked onto the end of February every four years accounts for Earth’s spinning around the sun five hours, 48 minutes, and 45 seconds longer than 365 days. In 46 B.C., Julius Caesar noticed the calendar had fallen behind 90 days and tried to correct the difference, and added days here and there to months on the calendar for one year, adding a leap day every four years thereafter. This still needed tweaking: By 1582, with 11 minutes a year left unadjusted, the calendar had shifted 10 days. The Gregorian reform of the Julian calendar introduced an extra day to make up the difference, with leap years of centuries divisible by four skipped.

Whatever. The bottom line is, I turn 12 this year, and I have Pope Gregory XIII and my mother to thank for it.

Leaplings have formed clubs over the years, like The Order of 29’ers, set up by a newspaper editor in Pittsburg, Kansas, in the early part of the last century. Since 1988, Anthony, Texas, has championed itself as the Leap Year Capital of the World: In 2012, the town’s three-day celebration included a car show, an ice hockey game, and a golf tournament. At the website of the Honor Society of Leap Year Day Babies (“spreading Leap Year day awareness” for 19 years), fellow leapsters and leapettes share tales of woe: children who thought their birthdays were taken away, parents begging and bribing doctors to fudge kids’ birth certificates to February 28 or March 1. The date seems to confound petty bureaucrats and government factotum alike. “When I moved to Oregon and went to get my driver’s license I was told there is no February 29,” Raenell Dawn, the co-founder of the Honor Society, who turns 14 (56) this year, tells me. “The DMV employee actually said to me ‘Are you sure it’s February 29?’ As if I wasn’t sure of my own birth date!”

Leapsters fall into two schools. There are those who think it’s a unique quirk, like having double-jointed thumbs or keeping an AOL account. And then there are those who think it’s no big deal. “All I do is spend time with my family and close friends,” Antonio Sabáto, Jr., the actor and former Calvin Klein model (born February 29, 1972), writes to me on Twitter. “Good enough for me.” I haven’t heard back from the rapper and actor Ja Rule (born February 29, 1976) or the motivational speaker Tony Robbins (born February 29, 1960), so I assume being an actual celebrity trumps leapster status.

I can’t help but think about my life more deeply every four years. Thinking in four-year periods isn’t uncommon—we have summer Olympics and presidential elections on leap years, after all. But, each February 29, I pause to take a life inventory. 16 to 20 marked the time from high school to college. From 36 to 40, I became a father and moved out of New York City.

There isn’t much of a Leap Day birthday canon. It’s a good enough birth date for Superman, although who knows what calendar the planet Krypton uses. Leapsters do have children’s books (sample titles: It’s My Birthday ... Finally! and Mommy, Where’s My Birthday?) and a young adult title (Leap Day). Probability theorists have a famous exercise called the “Birthday Problem.” First proposed by the engineer and mathematician Richard von Mises in 1939, the Birthday Problem determines the probability of a match in birth date given any number of people in the same room. (The probability reaches one half at 23 people.) In the original set-up and others, however, Leap Day birthdays are excluded to keep things uniform. Perhaps the most famous leap-day plot device appears in the 1879 Gilbert and Sullivan opera The Pirates of Penzance. Frederic, enslaved to pirates until he turned 21, is convinced to stay until he turns 84 because of his February 29 birthday. “You are the victim of this clumsy arrangement,” goes the lyric for the opera’s leap-year song, “Paradox.”

And then there’s Facebook, which bugs users to wish a happy birthday to close friends, family, and the pharma sales rep they sat next to on a plane that one time. Facebook tells the world my birthday falls on February 28 by default. For leapsters who celebrate on March 1 (about half of my leapling brethren are not, like me, strict “Februarians”), this is enough to ruin a birthday. Unless, of course, you just change your birthday to March 1. But the clumsiness of the arrangement is often enough to make me want to throw a fit. Just like a 12-year-old.