Sevent een years ago Wednesday, I knelt on a carpeted floor in a rented Seattle apartment, tilting a carrot cake I’d just finished baking and decorating with a big numeral “1” in grated carrots and a single candle toward a toddler I’ll call Eli, wobbly and uncertain on his feet, supported by his mother’s protective grasp.

On Wednesday, Eli turns 18 years old. His mother’s whereabouts are long unknown, but for my part, I’m not-so-secretly celebrating his entrance to adulthood. “Three more days!” I write on his wall on Facebook (where we are friends), as though he were coming into a million bucks on the day. Frankly, I’m just grateful that he lived to see it, because it wasn’t always certain that he would.

In 1992, one month after Eli was born, I was living with two single moms and their infant sons in an apartment in Seattle, where we all went to the same church. I had full-blown chronic fatigue at the time, and Eli’s mother and I shared a room. So Eli and I were effectively roommates. I used to kid his mother that I was Eli’s “official staff photographer,” because I have dozens of photos of him from that first year: peeking out from under my white down comforter, which he loved; looking like a beautiful, smiling tan baby (he was half Mexican, one quarter black, one quarter white); tunneling out of a snow cave.

There are other photos that I’ve been saving for him in a box decorated with his picture: photos of his biological parents and the couple who later adopted him; photos of my husband and me during the intervening time when we took him into our home.

I’ve been holding onto these photos for Eli’s whole life, hoping that some day I’d get a chance to sit down with him and go through who all these people were who loved him dearly, even though not all of them were able to stick around to tell him so themselves.

But the reason Eli turning 18 has me so excited, and why it’s fair to say that he’s excited  as well, is that that day might never have happened if I hadn’t been willing to do something very unusual when he was only a toddler. I reasoned with his birth mother to give him up for adoption, stepping in because I believed I had to to save his life. And it’s only now that I can see the absolute wisdom of having done so – now that we’ve both lived long enough to see the story played out.

Eli’s mom, my roommate Tina, was a smart woman who dropped out of high school and got pregnant in her early 20s in a one-night stand with a handsome Mexican waiter in Portland, Ore. Although Tina grew up in a well-off suburb of Seattle, raised by a British family along with their biological children, she knew nothing of her own parents, other than that they had met as students at the University of Washington, or of the black roots that formed half her own DNA. “I love your Malcolm X glasses,” I teased her once.

“Who’s Malco Mex?” she replied.

We bantered back and forth about her getting her GED and getting off welfare; she wrote me long poems about how much she looked up to me as a mentor. That said, I never felt like she was really leveling with me, and one day when I was home sick, she just snuck out for good, taking Eli, barely 14 months old, along with her very few possessions.

Afterward, she stayed in touch minimally. Life was hard on the streets, where I believe she had gone in a desperate search to “connect” with the roots she never knew and getting mixed up with the wrong people. It wasn’t going well. When I married a few months later, she did show up for our wedding, bringing Eli, who was shirtless under a small pair of overalls. I have a photo of the four of us from that day, too – my husband and me, Tina and Eli with a cut lip, holding tight to a balloon he carried.

Shortly after I got married, the phone calls started coming. It would be late at night and Tina would be calling collect from the pay phone at Harborview, Seattle’s renowned trauma hospital. Eli and she would be in the ER. She’d have been beaten up by one of her druggie boyfriends, and soon Eli was beaten up, too—knocked unconscious once, thrown up against a wall. We went to rescue him, his small body out cold on a gurney. It was the toughest thing my husband said he’d ever seen. I’d forgotten that specific episode until recently. “Beaten up” was how I remembered it; knocked unconscious as a toddler was the truth.

I knew I couldn’t keep taking these calls and coming to the rescue like this. This was a situation that would play itself out, and when it did it would do so badly. I ventured a talk into uncharted territory and started to suggest to Tina that she consider giving Eli up for adoption.

This wasn’t one talk but several, and the gist was always his health and safety, and a sense that if she didn’t want him there were certainly others who did—the ever-smiling happy boy whom everyone around him just loved.

Eventually Tina agreed. My husband and I were able to take him into our tiny apartment while an out-of-state adoption could go through with a couple we knew, who amazingly enough had been present at Eli’s birth. He stayed with us for several months when he was about 18 months old. Ironically, he remembers everything about the place: our cat, Paul’s truck, the layout of the apartment. I guess he felt safe there, with people he knew he could trust. There were also flashes of anger there that I saw in Eli, a deep, dark fury that came on suddenly and passed over him in waves. I attributed that to what he had seen, and experienced in his short life on the streets.

The story doesn’t have a completely fairy-tale ending, though it’s no longer necessary that it have one. His adoptive mom, Robin, who loved Eli tremendously, soon died of cancer in her early 30s. Friction ensued with the adoptive dad, who later remarried, and Eli spent time in not one, but two year-long reform schools. Today, he’s doing well, though. A third — or fourth if you count us — family stepped in recently to parent Eli through his last steps of childhood, and he’s happier than I’ve seen him since, well, he was in his crib.

I was pretty sure at the time that if I didn’t step in and do something — too sick to adopt him myself, I still wanted him to thrive — it would be too late. On Wednesday, as I rejoice with Eli and his new family on his 18th birthday, Eli and I both know what happened then, and what saved his life.

It’s a meld of the Moses in the basket story and some random thing I must have read in a fairy tale. I feel like I put this tiny being into a flimsy boat, a hollowed-out half-shell of walnut, as it were, and sent it floating down the river. Amazingly the boat stayed upright, despite the force of the current, and the contents arrived at the destination intact.

A Northern California journalist, Lily Giambarba Casura is the author of Gentle Medicine and host of the flagship site Healing Combat Trauma.