During the summer of 2011, a friend and I went to Costa Rica. We hung out in a slum called La Carpio for a few days and worked with the Costa Rican Humanitarian Foundation to serve that community. La Carpio’s population is made up of immigrants from Nicaragua who have fled the dictatorship of their homeland. La Carpio is the poorest place I’ve ever been or seen.

One day in La Carpio, we made (from rocks lying around), hand-mixed, and laid concrete flooring in a local artisan’s house (Sidenote: we did all of this as local men watched and said—in Spanish, as if we didn’t know the language—that we women should get into the kitchen. Ha!). Another day, we built and delivered (on foot) bunk beds to homes that had only one mattress for the entire family.

On our last day in La Carpio, some of the women who work at a CRHF kindergarten-ish school cooked us lunch and fed us, and then they let us play with the kids. We loved playing with the kids for so many reasons: we were a bunch of teenage girls who all loved babysitting and the like, and we all wanted to learn more Spanish (and there’s no better or less-embarrassing way to learn a language than by hanging out with young native speakers).

Most of the kids were happy to entertain us, but one little girl wouldn’t speak or even hold eye contact. Her nickname was Yelly, and her shy self wasn’t excited to hang out with strangers. She kept putting her head on the table or in her arms. Being myself, all I wanted to do was play with Yelly. So I talked to her in broken Spanish. I made silly faces. I made exaggerated sad faces. I tried to respect her space by talking to other kids, too, but I always came back to Yelly. I was persistent. Everyone else had left the table where the kids had been eating and were playing with puzzles or dolls, but Yelly and I remained at the tiny table. She eventually and slowly started coming out of her shell—giggling at my bad Spanish or looking me in my eyes for more than a split-second. Soon, I had her up and playing. She corrected my vocabulary a lot, with a smile on her face; how fun would it be to finally be the teacher? And by the time I had to leave, she was hugging my neck.

That night, back at our temporary home, our group (eight high school girls + two post-grad leaders) ate dessert and talked about the day. One of the group leaders—Lauren—who’d been with a different group at the same school a few weeks before, told me something that would stay with me forever: the last group had noticed shy Yelly, too, and some of them had tried to get her out of her shell, but they’d failed. Everyone had assumed that she was actually mute. But I had gotten in. I had gotten Yelly to not only talk but to interact. To giggle and teach and play and hug.

And that was the moment that I knew without any doubt that I would be a teacher.