“I was always the confidante, never the boyfriend,” he said. “When I was 15, I looked very young. I would stand in front of the mirror wishing I could know what I would look like in 10 years.”
His mother nudged him to audition for the school play, and he was cast as the Artful Dodger in “Oliver.”
“I finally felt like, ‘There I am,’” he said.
He no longer minds so much that people still identify him with the work he did in the ’80s. “When I go, it will be ‘Andrew “Pretty in Pink” McCarthy dies’ — which is fine!” he said. “I ran from all that for years.”
Readers of his best-selling travel memoir, “The Longest Way Home,” know that by his 30s he had stopped drinking and rediscovered that feeling of “there I am” by going it alone to far-flung places. He kept a notebook and spent a year trying to persuade a travel magazine editor to give him a shot. He has since published dozens of travel essays and has won awards, including the 2010 Travel Journalist of the Year from the Society of American Travel Writers.
Before dedicating himself to his young adult book, Mr. McCarthy spent seven years working on a novel “about a married guy who had a one-night fling and had a child and spent 25 years keeping it a secret.” It was terrible, he said. Then, one day, while waiting for a plane to take off, he started writing from the point of view of his favorite character, the 15-year-old daughter.
“I was just messing around,” he said. “I would do anything to avoid writing the other book.” The pages came easily, and he realized “the big novel was like a dead tree in the woods and this was a nurse tree that sucked up all the roots.”
His protagonist, Lucy Willows, lives in an unnamed New Jersey town based on Westfield, where Mr. McCarthy’s family lived until he was 15, when they moved to Bernardsville. Furious at her father after learning about her secret half brother, Lucy jumps on a train to New York City and ends up on a solo journey to Maine.
Mr. McCarthy said he had not read any of the recent, similarly realistic young adult novels by the likes of John Green and Rainbow Rowell, who have become publishing juggernauts. But he has embraced the idea of writing for a teenage audience. “I thought, if there’s truth in this, it would be a book for that extraordinary teenage moment in life, because everything is so important, it’s life and death, and you’re the only one who’s ever gone through it,” he said.
He tested a draft on a teenage neighbor, who told him Lucy’s voice sounded legitimate.
A waiter approached with a soda refill, prompting Mr. McCarthy to sweep a copy of “Just Fly Away” out of view. “They’d start asking about it,” he said apologetically. “I’ve come here for years and years.” He lived nearby briefly, but these days he lives in the West Village with his wife and three children, one from his first marriage. “I’m very happy down there,” he said. “I’m basically walking the same streets I walked in college” — he spent a few years at New York University before leaving to act full time — “but it’s different every day, and now I’m doing it with kids and a dog.”
After lunch, we headed to Teavana, where he ordered a takeout darjeeling. “My wife is Irish,” he said. “I now drink tea all day.” While we sat on a bench in Central Park, at times saying nothing, I recalled his description of a teenage character in “Just Fly Away”: “a loner who likes to mingle.” It’s the vibe Mr. McCarthy gives off.
In addition to writing and directing for television, Mr. McCarthy has also become a somewhat reluctant stage dad. His daughter, Willow, played Matilda in the Broadway production of “Matilda the Musical,” which closed on Jan. 1.
“We went to see ‘Matilda,’ and she was like, I want to be in ‘Matilda,’” Mr. McCarthy said. “At that point she had been the frog in the school play; she was not an actor. I was like, O.K., sweetheart. So the babysitter was looking online for all things ‘Matilda,’ and there was an open call and Willow was like, ‘Can I go?’”
Five auditions later, she won the part that she played for eight months.
“She was wondrous and wonderful, and she loved it,” Mr. McCarthy said. “I saw ‘Matilda’ 50 times. Luckily, it’s a great show. She gave the last performance of ‘Matilda.’ I found it very stressful. It was all the anxiety of performing but none of the release. It’s like watching your heart outside your body.”
In the meantime, his oldest son, Sam, has acted in a few TV shows. “It’s everything I said would never happen to my children, and now here I am,” Mr. McCarthy said.
Recently Sam was cast in the indie movie “All These Small Moments.” His mother will be played by Molly Ringwald, Mr. McCarthy’s co-star in “Pretty in Pink.”
“After the first day of rehearsal, Molly emailed me and said, ‘Your son just walked away from me and it was like watching you walk away from me 30 years ago,’” he said. “It was very sweet.”
As Mr. McCarthy posed for a photograph under a bridge, a woman of a certain vintage called out, “I just have to say — a lifetime! You look great.”
He stared serenely into the distance.