Every summer of my childhood, my parents dropped me off at a month-long overnight camp in New Hampshire’s rolling, green hills. A quiet girl, I was often intimidated by my outgoing bunk mates. And so I usually found myself sitting cross-legged in my dark bottom bunk, writing “I miss home” to my mother on personalized rainbow stationary as I blinked away tears.

This memory probably isn’t that extraordinary. Kids and teenagers, whether at summer camp or a semester abroad, are expected to be homesick. But if I told you that I am now 29 and just as homesick as I was at age 10, you might wonder why I’m acting so childish. In fact, I’ve often sighed and asked the same question: Why am I being such a baby?

Sixteen months ago, I did something many people in relationships do: I moved from my home city of Boston to New York because my live-in boyfriend got a new job here. The timing was good — I had just finished graduate school and would be searching for writing and editing jobs. Where better to look than the Big Apple?

In the past, I’d flourished away from home while at college in Upstate New York and at my first job in Washington, D.C. But once I had finally returned to my home state, I was ready to stay put, which made leaving once again more difficult than before.

Even though I am nearly 30, this change made me revert to that sniffly homesick camper with bags under her eyes. Since moving, I’ve experienced a sort of homesickness that’s been difficult to explain, even to myself. I often find myself thinking about what I’m missing at home: helping my father put up his wacky Halloween decorations as he rants about the latest Celtics trade rumor, reading in the sun room with my mother until we see five deer gallop through our back yard, chasing around my toddler cousins at family gatherings. I feel a deep sadness and longing for these moments, one that I cannot shake through logic.

I try to tell myself it’s no big deal, that I’ll visit soon. But still I cry at the drop of a pin. There are knots in my stomach about half the time. I have trouble falling asleep or sleeping through the night.

Here’s the confusing part: I am happy in my life in New York. I have a rewarding job at a publisher; a boozy book club; a boyfriend who makes me laugh and does the dishes. So what gives?

When I spoke with Michael G. Thompson, author of “Homesick and Happy: How Time Away from Parents Can Help a Child Grow,” he said that homesickness can strike adults, even though we’re used to associating it with childhood. Adults might say “I’m having trouble transitioning” or “I miss my friends,” but the word “homesickness” just isn’t in their wheelhouse, Thompson said.

Perhaps it should be. History and literature alike — from the Civil War to “The Odyssey” — have taught me that yearning for home is a universal feeling. Back in the 1800s, it was viewed as callous if you didn’t feel ill leaving home, as if you didn’t love your family enough. Even earlier, homesickness kept our nomadic ancestors from abandoning their clans, since doing so could bring them into harm’s way.

Susan J. Matt, author of “Homesickness: An American History,” tells me that our perception of homesickness has evolved to meet 21st-century expectations about mobility. Nowadays, leaving home is supposed to be no big thing. At age 18, it’s up and at ’em, off into the world.

I rarely own up to feeling homesick because I worry that it makes me sound weak. When my parents or friends call to catch up, I offer details of my New York life: “I gave a presentation at work,” or “We tried a new Chinese food takeout spot.” I certainly don’t say: “I’m deeply homesick and it’s frustrating, tiresome and even slightly humiliating.”

According to Matt, one theory says that kids with close-knit families might experience homesickness more as adults, because the culture of unity they grew up with makes absence more difficult.

So why should I be embarrassed that I was raised by wonderful parents who I wish I could spend time with, in a home where I feel at peace? The next time I’m feeling down, I’m not going to call myself a baby. Instead I’ll try calling myself something else: lucky as hell.