Leaning perilously over the display at the Yale University Art Gallery, the boy wasn’t quite sure what to make of artist Mona Hatoum’s quaint crystal orbs.

“They’re grenades, honey,” his father said perplexedly, reading the description of Hatoum’s piece, titled “Nature morte aux grenades.” Upon closer inspection, what I had imaginatively taken for pomegranates protruding wartlike across a hospital gurney proved, indeed, to be grenades. The three of us clustered awkwardly on one side of the gurney, staring expectantly at the little bulbs as though waiting for them to either explode or explain themselves. Silence ensued as before.

A guard nearby, coming suddenly to life from totemic stillness, shifted towards our company. I glanced at the child’s fingers, which had probably strayed too close for comfort and were now to be chastised. Instinctively, I stepped back, recalling with unfortunate clarity being criticized for touching museum pieces I ought not to be touching. We fixed ourselves like the grenades on the gurney, willing our bodies safely away from the art. It was the guard, though, of ursine proportions and with hands the size of Frisbees, who seemed more likely to crush the collection.

But when he spoke, it was not, as I had thought, to usher us aside. “This is one of my favorite pieces,” the guard said. We looked at him, taken aback, as he proceeded to explain the work and the artist’s history. He was, clearly, no tour guide. Still, he continued as though he were, animatedly evincing a knowledge of the art more encyclopedic than I would ever have imagined from one whose task it was to stand by and secure art, not study it. First fruit had become firearm, and now security guard had become scholar. The guard’s name, he said, was Jerry Gray.

***

After 14 years of renovations, the Yale University Art Gallery reopened in December 2012 to fanfare from visitors and journalists alike. Heralded as “magnificent” by The New Yorker, the YUAG was praised for its balanced collections that feature not only marquee pieces like Van Gogh’s “Night Café,” but also smaller, unexpected works by artists both famous and forgotten.

The YUAG’s attention to the small and unexpected filters down to its security agents. Although Gray is a notable example, he isn’t the only guard who has taken more than a passing interest in the gallery’s offerings.

Visitors to the gallery have noticed the guards’ excitement. One wrote in a letter, “Typically, the security in museums big and small [is] more like the statuary they protect. The enthusiasm I felt when I left your museum was due in no small part to their enthusiasm for the museum, too.”

Gray insists he doesn’t know as much as I thought he did about the gallery. He says he’s studied a bit (“I did a little reading”), favors contemporary art (“Sol LeWitt and Pollock”) but also goes for the classical ­— in other words, his is an interest no more remarkable than that of your average amateur, he seemed to assert. Still, it’s hard to imagine LeWitt or Pollock preferring a viewer told by textbooks and lecturers to venerate their works over one like Gray, who has come to art of his own accord.

“People are floored that I know things about the art,” he said, with a touch of pride. “But if I’m interested in it, I’m going to learn about it.” I pointed out that not everybody takes such initiative, and he shrugged. “That’s just how I am.”

Despite his familiarity with many of the works in the gallery, Gray claims that he doesn’t have a favorite piece. Shaking his head, chuckling and shrugging his massive shoulders, he said that he loves “all the art.”

“I love working in the Trumbull gallery,” he conceded. When I asked why, he widened his eyes, surprised that I didn’t know. Gray explained that Trumbull, a Harvard graduate, agreed to display his collection in the Yale galleries only under the condition that he and his wife be buried beneath his portrait of George Washington. It’s one story among many Gray likes to share with the people passing through his watch.

Gray might be oversized, but there is no doubt that he is exactly where he belongs at the YUAG. Towering sturdily over his painted wards, he could be art himself, an ambitious artist’s exploration of the majesty in bulk and brawn. A sculptor might labor to make his face as full and self-assured as in life, to painstakingly chisel the manifold pleats and tucks in his cheeks that deepen when his lips let loose a smile.

Gray is the kind of person around whom you feel either very safe or very scared, depending on your side of the law. As important as art has become to him, apparent in his largeness is that something else has held his heart far more tightly, and for far longer: football.

***

Gray has spent the past 17 of his 45 years coaching football. Next year, he is poised to be the defensive coordinator of a new minor league pro team in Connecticut, the New Haven Venom. The day after he interviewed for the job, he was hired.

“I am very, very good at coaching,” Gray said. It wasn’t bragging, just affirmation of what he knew to be fact. His tone left no room for doubt. “I’m going to coach till the day I die.”

It’s a passion that has been fermenting since he started playing at the age of 5. Football became his “saving grace,” a place of comfort from a host of anger management problems. Gray’s father, a former football player himself, encouraged his burgeoning interest in the sport.

That he was right for athletics became immediately apparent. As a child, he once “tackled a high school guy who weighed 270 pounds.” Unable to stop myself, I asked him how much he weighed at the time, as by his own admission, Gray was “always big.”

“I wasn’t 270, I know that,” he responded grimly. “But I went at him hard. … I had no fear.”

In Gray’s adolescence, a number of coaches noticed his talent. The first, Ron Carbone, a high school coach from Hamden, recruited him when he was only 12. Big and fast, Gray made an impression on each who saw him play.

He seemed disarmingly nonchalant about the injuries he received on the field. “My mother was fine with football. It was actually my father that freaked out” about Gray’s bruises and bumps, he said. In high school, he rolled his ankle. Then, playing defensive lineman for Western Connecticut State College, he broke his neck, a fact he revealed only after I pressed him further. He broke his neck — then continued to play.

“I lay on the ground, screaming,” recalled Gray. “I knew my career was over. Then I got up, said nothing to the coach, and kept playing.”

The accident left the entire right side of his body partially paralyzed, and Gray, unwilling to acknowledge the end, became a left-handed player. “Luckily, I’m [naturally] left-handed,” he said, although his resulting condition would take its toll on him by the end of the season. Gray explained that he had gone to college solely to play football as the only freshman starter in New England’s Independent Division 3. In the permanent, jarring absence of the sport that had first saved him, then ruined him, he lost all motivation to finish his education. Gray came home and went to work at a dry cleaner’s.

***

In May 2011, after Gray crossed the stage at Albertus Magnus College to receive his diploma, the first thing he did was hold it skyward. Absent from the audience was his father, who had died of cancer four years ago.

“That moment changed everything,” he said. “It destroyed me.”

After his stint at the dry cleaner’s, Gray had been flitting between jobs, eventually entering the security business when a friend pointed out his size would be an asset in that industry. Still, he recalled a promise to his father to complete his education. Eleven months after his father’s death, Gray enrolled at Albertus Magnus. He received his associate’s degree in business management from its New Dimensions program, which allows students to simultaneously pursue their careers and attend school.

He chose to continue his studies at Arizona State University last year, but had to return home after developing soft-tissue sarcoma, losing the entire left side of his chest in surgery. Back in New Haven, he sought work in security once more, learning about an opening at the YUAG. Gray impressed with his friendliness and excitement for the job, said Joshua Ramirez, his current supervisor, and he was hired.

In the six months Gray has been at the YUAG, his excitement has only bloomed. “People tell me, ‘You should be a tour guide!’”, he said, though he has no plans to apply.

Gray doesn’t think his position at the New Haven Venom will require him leaving the gallery, “but if it does, it does,” he said. Then he paused, seeming to reconsider. “I don’t know. … I like it here. I like everything about this place.”

***

Ramirez said his staff dissuades the guards from overstepping their responsibilities as security agents. “We don’t want to infringe on our [visitors’] experience,” he added.

But visiting an art gallery is in itself an infringement — on expectations. The experience of viewing art is necessarily a displacement of assumptions about color, perspective, form, composition. Verisimilitude, even in the exact sketch of a subject’s plump form or a gnarled tree branch, is only ever a coincidence. If in art audiences sought only the quotidian, the seen and foreseen, creators might set down their tools; real life would suffice. Art succeeds most when it challenges us.

At the YUAG, the gauntlet has been thrown. There, art is a crystal pomegranate that becomes a grenade. From 9:15 a.m. to 5 p.m., art is a security guard named Jerry Gray who becomes a storyteller.