Although Dr. James C. Wittig hasn’t legally adopted Ronnie, whom he’s raised since the age of 13, he tells PEOPLE the now-20-year-old “thinks of me as his dad”

James C. Wittig always wanted to be a dad. The single, never-married physician joked that he wished he could start fatherhood with a 13-year-old. Then, one day, he was scrolling through Facebook and saw a former patient was trying to find a home for a teenage boy whose parents had both died. Wittig volunteered and went on to raise the boy.

“I wanted a child,” Wittig, an orthopedic oncologist, tells PEOPLE. “I must have been sending these messages out to God and in prayer and everything.”

As it turned out, the physician had another connection to the boy, although he wouldn’t discover it until they’d been living together for months.

Nearly 25 years ago, his fellowship director gave Wittig a photo of two osteosarcoma patients he had treated in the early 80s. The two women in the photo both had the same kind of bone cancer, but had two different treatments: one patient had a limb amputated, while the other underwent limb-sparing surgery.

When he was a fellow, Wittig cared for the patient whose limb was spared. And when her physician, the fellowship director, retired, Wittig became her doctor.

For years, Wittig — who now works at the Morristown Medical Center, where he’s the Chairman of the Department of Orthopedics — used this photograph when giving lectures and training residents. “It shows the difference between a person who has their legs saved from cancer, versus one who has an amputation for it,” he explains. “It gives a visual when you talk about limb-saving surgery and talk about osteosarcomas.”

Although he had a professional relationship with the woman whose leg was spared, he never met or treated the other woman in the photograph. But after she died, he went on to raise her son.

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In 2015, Wittig, who kept in touch with his former patient, saw on Facebook that she was looking for someone to care for a boy named Ronnie, the son of a friend who died of complications from her amputation. The boy’s father had recently died as well.

“I reached out to her and I said, ‘I really want a child in my life,'” Wittig says.

About a month later, in February 2015, Wittig drove from his home near Morristown, N.J., to northern Virginia to meet the boy in person.

“He was an adorable, kind, caring, energetic kid who was very loving,” says Wittig.

Shortly after that visit, his patient called and said Ronnie would like to come meet Wittig’s family.
Hours after the second visit, Wittig learned the boy had decided to live with him

Two weeks later, Ronnie’s legal guardianship was transferred to Wittig and the boy moved in that March.

“He is one of the strongest and kindest and most courageous kids that I know,” he says of Ronnie, who went on to attend Seton Hall Prep and just graduated from welding school.

A few months after living together, Wittig realized the boy’s mother was the other woman in the photograph he had used in presentations for many years.

“I see this whole thing as a synchronicity,” he says. “The coincidence of me getting his mother’s photo handed to me when I was just starting as a fellow, to me looking back at everything: It was meant to be.”

Wittig still hasn’t legally adopted Ronnie, now 20, but says maybe they’ll complete the process in a year or so. “It’s really just a paper,” he says. “He thinks of me as his dad.”

Being a parent and having a child to “love” and “care about” has been “so fulfilling” for the oncologist.

“I can help him, and guide him through life, and help be his coach. And in the same regard, he’s my coach. He teaches me every day,” Wittig says, sharing that from his son he’s learned multitudes about “kindness, compassion, empathy, love, joy, and happiness.”

Wittig hopes his story will encourage other older, unmarried men and women who want to be parents to realize that it’s not too late.

“Whether they’re adopted or blood, they’re still your children and it’s still the same exact thing,” he says.