You never know when a single moment is going to creep up on you and change your life. For Sandy Sondheim and Horace Knox, it all started with a full bladder.

Sandy, 83, lives in Brunswick. Horace, who just turned 74, lives in Lewiston. Sandy, a man who revels in a good joke, is a retired teacher. Horace, who’s developmentally challenged, blind and almost deaf, has a passion for electronics.

This is their story.

It was the summer of 1963. Sandy, then 25, had recently moved to Maine from Massachusetts.  He’d served as a volunteer with Big Brothers in Boston and, while busy launching his teaching career here, was also on the lookout for other ways to contribute to the greater good.

He had two friends who worked as staffers at what was then the Pineland Hospital and Training Center, formerly called the Maine School for the Feeble-Minded, in New Gloucester. They knew about Sandy’s background with Big Brothers; they also knew that residents of Pineland – at the time the place of last resort for children and adolescents with any number of cognitive, emotional and behavioral difficulties – needed all the outside companionship they could get.

“Come with us,” they suggested to Sandy one day. “We’re taking a busload of kids to Sabbathday Lake for a picnic.”

“Sure,” Sandy replied. “But what do you want me to do?”

“Just watch,” they told him.

So he did. An hour or two into the outing, a 16-year-old boy stood up and announced loud enough for all to hear, “I’ve got to take a piss!”

A staff member guided him to a clump of bushes a short distance away. There, as he relieved himself, he looked over his shoulder and hollered, “It’s getting so a fella can’t even take a leak by himself anymore!”

Sandy, standing nearby, chuckled at the teenager’s audacity. “That’s my guy,” he decided on the spot.

Much of how Horace came to live at Pineland is lost to history. He grew up in the central Maine town of Anson. When asked about his family during a visit to his apartment Thursday, he quickly replied, “I wish you didn’t ask me that. They don’t even know me.” Then he broke down in tears.

But Sandy knows him. Week after week, month after month, he kept coming to see Horace. They bonded so immediately that Horace soon began calling Sandy “Dad,” a name that sticks to this day. Monique, Sandy’s wife of 53 years, just as quickly became “Mother.”

Horace’s stay at Pineland lasted a relatively short three years. But it left its mark: He lost his vision, he said, after getting into a fight with another resident.

Then one day in 1965, as Horace tells it, “They said, ‘We don’t need you here. We’re going to send you to Bangor.’ Well, they sent me to Bangor and the doctor there says, ‘You ain’t crazy. I’m going to find you a home.’”

Thus began a seemingly endless succession of foster homes, boardinghouses, group homes – upwards of 60 in all over more than half a century.

“I trashed every one of them,” Horace said. “Nobody wanted me.”

Still, as the months rolled into years and then into decades and Horace’s past addresses multiplied like so many pins on a map of Maine, Sandy kept coming. He sensed Horace’s fierce longing to be independent. He understood that deep inside this sometimes abrasive human being lay needs that Sandy, simply by showing up, could help meet.

Latching onto Horace’s aptitude for all things electronic, they’d work on projects together – reviving an old radio, spooling up a reel-to-reel tape recorder, listening to vinyl records on an old stereo. Every May 19, Horace’s birthday, Sandy would take him out to dinner. Other times, as Horace grew into a young man, they’d go out for his favorite combination – an ice cream sundae washed down with a cold root beer or, as Horace grew older, a “real beer.”

“Basically, he wants to be who he is,” Sandy said last week. “It would literally kill him – you know, slowly – if he were put in a group home” at this point in his life.

It’s been 10 years since Horace moved into his small, first-floor apartment on the edge of downtown Lewiston. He’s so familiar with his surroundings that a first-time visitor might at first not realize he can’t see.

How does he navigate the tight quarters so well?

“I just do,” Horace replied, reaching for an animal cracker from a bin on the kitchen table. “And when things get moved around, I don’t like it.”

He still has the screws used a few years back to repair his broken hip after a hit-and-run driver struck him at a corner a few blocks from his home. He’s had a pacemaker installed, along with a bovine “cow valve,” as he calls it, to keep his heart beating properly.

“And I have no teeth,” Horace divulged.

No teeth? What about that animal cracker he’d just popped into his mouth?

“I have jaws of steel!” he loudly boasted.

Through it all, the one constant has been Sandy. He’s hardly the only person helping Horace maintain his treasured independence – caseworkers from two social services agencies, emissaries from two local churches, a woman Horace calls “Grandma,” all pitch in at their appointed times to keep him afloat.

Sandy, while on a first-name basis with all of them, stays mostly out of the day-to-day bureaucracy that underpins his friend’s very existence. Rather, his job is to be the family that Horace lost along the way, to tell him a joke, to lend some roots to a life that otherwise would have none.

Last week, it was all about an old humidifier. It sits in Horace’s bedroom and still works like a charm. But the cracked plastic top – jury-rigged together with a piece of plywood with various ventilation holes drilled through it – is no longer satisfactory as far as Horace is concerned.

“I don’t know if we can make a new top for it or not,” he told Sandy. Moments later, there was Sandy, tape measure in hand, getting the dimensions for a new, quarter-inch plywood top.

“This is very typical of what Dad does around here,” Sandy told me. Back home in Brunswick, he’ll scour his scrap wood pile, maybe go to the lumber yard if necessary, and fashion a new cover for installation during their next visit.

Why do it? Why not bask in his twilight years with Monique rather than maintain a 40-mile-round-trip friendship that easily could have dissolved decades ago?

“Because I feel dedicated,” Sandy replied, simple as that.

Dedicated doesn’t begin to describe it. Nor is there any doubt how long this bond will last.

“Until he dies or I die,” Sandy said.

Long live them both.