There's an expression that was my mantra through college: "Peace Corps, the toughest job you'll ever love."

The idea was that after graduation I would join the Peace Corps, and do the toughest job I'd ever love. In 2002, I arrived in Washington, DC for orientation to teach in Romania. I sat terrified in a conference room thinking about the next 27 months.

The first thing I remember was a guy raising his hand and asking the Peace Corps official, "Is it true that 80 percent of volunteers come back married, engaged or in love?" I was floored.

Here I was trying to imagine what Romania looked like and where I'd be living. I had never even considered love. Janice Sims was one of my fellow volunteers in Romania. It turns out she was just as surprised at the mention of love at her Peace Corps orientation.

"I don't remember a percentage being put on it, but I thought a large majority," she says. "And I thought, that's not going to be me."

Janice joined the Peace Corps to work on environmental projects abroad. She helped to develop the first recycling program in our town of Ramnicu Valcea. She was also getting over a painful divorce. Love was the furthest thing from her mind.

Then at her orientation in Washington, DC, Janice was handed a slip of paper with the name of a random country. It was one of those icebreaker games. The instructions: find the volunteer with the corresponding capital of that country and introduce them to the group. Someone named Glen Harrison had that corresponding capital city.

"Through the skirmish when we were looking around I heard out of my ear someone say Thailand," says Glen. "I tapped this person on the shoulder…and it was Janice." For Glen, if it wasn't love at first sight, then let's just say he was really interested.

The meeting broke up, the volunteers scattered to take advantage of one final night stateside. Glen asked Janice if she wanted to go with him to see an orchid exhibition at the botanical garden. Janice quickly refused. "All I could think about was, can't do it, sorry, and I'm certainly not going to go see any orchid exhibit," recalls Janice.

"That is way too forward. We are moving way too fast. I know what orchids mean — and no."

Things do move fast in the Peace Corps. Relationships form quickly. What might take six months to develop under normal conditions might, in the Peace Corps, happen in six days. Janice and Glen became instant friends. But Janice questioned any romantic feelings toward him.

"You don't know this person, they're not meeting your family," she says. "You start to think to yourself, can I trust this person? Should I trust me with this person?" For Janice it came down to: "I have to trust this person because this is the only person I got."

Helen Fisher, a biological anthropologist and love researcher — yes, love researcher! — is not surprised that people in the Peace Corps fall in love. Not only did Janice have to trust Glen, says Fisher. She was chemically programmed to trust him. When you leave everything and everyone behind, your brain is hardwired to rebuild a daily life with another human being, according to Fisher. And your body responds.

She says change triggers an increase of dopamine in the brain. "It's very easy once the dopamine activity begins," she says, "to rise to fall madly in love."

A little adventure doesn't hurt either. Like, say, nearly falling off the edge of a mountain. Three weeks after that first day in Washington, Janice and Glen found themselves descending a snowy mountaintop in Romania, on a day off.

They are both experienced mountain climbers, but that day the trail down was a giant ice luge. "It must've taken us six hours to climb down this thing and we fell about 500 times," says Glen.

A couple of times they thought that we were just going to slide right off the mountain. It was "really, really nasty."

"And really, really tense," says Janice. But they made it down. At that stage, they were still just friends. On the train ride train home, "we were just so extremely tired … and stressed," says Janice. "I remember I just fell asleep on Glen's shoulder. I think that was when I fell in love with him."

How common is falling in love in the Peace Corps? Eighty percent sounded like an insanely high number when I first heard it mentioned back in Washington, DC.

But Ken Goodson, an advisor in the director's office at Peace Corps headquarters, told me that in his experience, it's true. He estimates that among the number of volunteers in the places that he's worked, more than 75 percent, over the duration of their 27-month commitment, "find themselves in love." But in an organization with a manual for nearly every conceivable situation, there is surprisingly no policy on love.

Often, when it's time for the host country Peace Corps staff to assign where volunteers will live and work for two years, couples might ask to be placed close to each other. "As staff you have to struggle with that a bit," says Ken. "Do you want to keep them together?"

It might make them happy — assuming that their relationship continues to flourish. Or do you want them apart, "so that they're more focused on the service commitment and less on the personal commitment?" But there are no guidelines.

And there are no guidelines because no rules apply. Peace Corps is about relationship-building. Sometimes your service commitment gets entangled with your personal commitment.

Jamie Schehl met Youssou Diatta while on assignment in Senegal. Youssou, who is Senegalese, was building a cultural school in his village. Jamie was helping him write grants and manage the project. They became good friends, and then they fell in love.

After Jamie finished her Peace Corps service and went back to the US, Youssou applied for an American fiancé visa. A few weeks before he left for the US, the cultural school burned down. It was a huge blow and it brought into focus an issue that had troubled Jamie.

"I felt a little guilty because he really was the leader," says Jamie. "The buildings burning down were really bad, but the truth is, what was even worse was Youssou leaving. I think without his leadership — I think that more than the buildings burning down — [this] led to the demise of the group and the project."

Love was taking Youssou away from his community at a critical time. Romance was getting in the way of the very work that Jamie had joined the Peace Corps to accomplish.

"There was some guilt there," says Jamie, "but I still feel strongly that, in the long run, it has helped Youssou's country and his family by having him here."

Youssou is close to graduating from college, after arriving in the US with a 6th grade education. Youssou dreams of one day returning to rebuild the cultural school. But for now, thanks to better mobile and Internet service in Senegal, he still considers himself a leader in his village — just by proxy.

People call him all the time for advice or financial help. Still, he acknowledges the split he feels between the U.S. and Senegal will never go away. "It's hard to be just in one place," says Youssou. "You feel like you're heart is in the other side, but you go in that place and you feel the same way about the other side."

For better or worse, not everyone falls in love in the Peace Corps. I returned from Romania as single as I left. Was my timing off? Was the dopamine not firing in my brain? Or it could be, as the Romanian superstition goes, that I sat at the corner of a table one too many times?

Whatever the case, I was happy witness to many, many Peace Corps romances. Janice and Glen? They now live in Washington, minutes from that Holiday Inn where they first met. "Sometimes we walk in the lobby," says Janice. "The Holiday Inn guy is always like: 'Can I help you?' And I'm like: 'No, we're just going to stand here next to the elevator bay.'"

"You know, just to get the aura of the day we first met. Because that's where I sprang the orchid question to her was in the lobby of the hotel," says Glen. "And since then we've gone to the orchid exhibit a lot," says Janice.

A few years ago they were married quickly and quietly by a judge, on their lunch hour. I never got to give them a proper toast. I had the speech all planned out. To the toughest job you'll ever love: marriage.