NEW YORK -- People say that in life, there's only one certainty -- and that's change. All it takes is one moment, and life is never the same.

One day, you could be a marathon runner training in Prospect Park when you see two children who are about the same age but whose lives are worlds apart. One was on a bicycle, joyously exclaiming to his father that he was going so fast and that he was so happy. And the other was in a wheelchair, gazing longingly at an experience he had knowledge of but no relation to.

The next day, you could be the founder of a nonprofit organization called AdaptAbility, using your expertise in mechanics as the owner of a bike repair shop called "Behind Bars in Brooklyn" to build custom-made bicycles for children with disabilities.

That's what happened to Sandra Alfonzo in the summer of 2015. It was the moment that changed her life.

"It broke my heart," Alfonzo said, "and I decided to make a difference and to do something to help all those kids out there."

All of which led to Friday -- the fifth and final day of the Yankees' 10th annual HOPE Week -- when Yankees manager Aaron Boone and players Aaron Hicks, DJ LeMahieu, Cameron Maybin and Adam Ottavino joined Alfonzo in surprising Kiko, a 14-year-old with special needs, with his very own adaptive bicycle.

"It's awesome that you stopped what you were doing, because we're all so dang busy all the time and we've got this idea that we've gotta have our blinders on and just be concerned with what's in front of us, not necessarily the people that are around us," said Jason Zillo, the team's vice president of communications and media relations. "And it's kind of cool, I thought, that we're trying to do, during HOPE Week, what you are doing for kids with disabilities.

"You stopped for a second and you said, 'I'm able-bodied, I've got 24 hours a day and I can potentially do something with my craft.' And that's what you're doing, and you should feel awfully proud of yourself."

In just a year and a half, AdaptAbility has provided unique bikes for eight families. Since it takes two to three months and $4,000 to $5,000 for Alfonzo and her small team of volunteers to build each bike, there is an application process to choose each recipient.

So when Kiko, who is partially disabled on the left side of his body and is partially blind out of the left side of his eyes after having half of his brain removed, applied with the help of his parents, Joseph and Lina Mina, he had no idea that he would be chosen, let alone that the Yankees would end up giving it to him.

But much of life is rooted in fate. There's this idea that every person exists in an interconnected chain, and that no two people are separated by more than six degrees. The Mina family is now well-acquainted with this philosophy.

Last summer, Kiko attended a weeklong bike camp in New Jersey courtesy of the iCanBike program, part of a nonprofit organization that provides quality learning opportunities in recreational activities for individuals with disabilities. It was hosted by an avid cyclist named Mitchell Morrison, who went on a one-on-one bike ride with Kiko and fell in love with him. So, Morrison invited Kiko and his parents to his upcoming Tour De Farm event, where he introduced them to his friend Marty Epstein and Epstein's children.

It just so happened that Jonathan Epstein was involved in InTandem, a not-for-profit organization that provides tandem cycling programs mainly for the visually impaired in New York City. After noticing how difficult it was for Kiko to ride solo, he volunteered to teach Kiko and Joseph how to ride together. Jonathan then sent an email to the Minas' about a woman he knew who ran a program in Brooklyn that gives bikes to disabled children. The application deadline was that night.

The Minas decided there was nothing to lose. As it turned out, there was so much to gain.

On Friday, Kiko walked into the bike repair shop and immediately noticed that there were more people around than usual, making it known that he had "no idea what was going on." That's when Zillo called Boone and the Yankees players out from their hiding spot behind a curtain. They rolled out his new tandem bike along with them -- as well as a custom helmet with the Yankees logo on it.

Kiko and his parents were overwhelmed by the surprise, effusive in expressing both their shock and gratitude. Alfonzo noted: "I've never seen him this happy."

"Oh my gosh, it is amazing. I love it," Kiko said. "The bike, but especially the presentation. I can't wait to ride it back [home]. It's crazy, I wasn't expecting them."

Added Boone: "God bless her. The fact that she continues to do this and to see the impact it's having on a family, this is what it's all about. HOPE Week is the best thing we'll probably do all season. To be able to touch different people's lives, but ultimately, it ends up touching us more probably than even the people that we get to affect. It's a great thing we get to be a part of."

The Yankees weren't just there to be bystanders, though. They were set to accompany him to a park down the block to take the bike out for its first spin. Maybin jokingly asked Joseph if his legs were ready. Joseph turned to his son and said: "You got a lot of athletes here to help you, do you want them or me?"

When Kiko didn't show a preference, Maybin took Joseph up on that and hopped on the back. He guided Kiko across the intersection and down the street, while the rest of the group tried to keep up on foot. At the park, Maybin took him around a couple times, as did Boone.

Both of them talked about how it was a "smooth ride" with an "easy handle," so when Joseph took up the rear, he let Kiko do some of the pedaling and steering himself.

After they were done riding, Zillo called the group together to make a special announcement. Kiko and Alfonzo would be throwing out the ceremonial first pitch at Friday's Yankees game vs. the Astros. Kiko, who used to play adaptive baseball in the Little League Challenger Division, lit up with excitement. It would be the Minas' first time at Yankee Stadium.

The Yankees had one more surprise in store for this year's HOPE Week, and this one was for Alfonzo.

"I just wanted to say this," Zillo said, "You saw all of our players and our coaches and our manager and we bring all this attention, and I know you're thankful for them being here, but Sandra is the one that built it."

He then presented her and AdaptAbility with a $10,000 check to carry on their work.

"Oh my God, I have no words. This is amazing," Alfonzo said. "[The Yankees are] wonderful, you can see that they really want to help people just like we do. … I really, really hope it will help my organization so we can help more kids."