Shortly after Justin Bieber‘s Purpose World Tour began, he made the executive decision to eliminate all future meet and greets (purchased by his most fervent followers at a hefty $2,000 price tag), doing for himself what no one would do for Britney Spears circa 2007: He put his mental health and well-being above the almighty dollar.

The concerts themselves have continued as planned, along with the underlying expectation that Bieber -- no longer overwhelmed by emotionally taxing one-on-ones before the show -- would be back onstage at his best, batteries fully recharged. But the Energizer Bunny he is not, and judging by his May 4 performance at Brooklyn’s Barclays Center, he'll soon be running on empty.

The show kicked off with Bieber hovering high above the crowd, encased in glass. He launched into a passionate performance of "Mark My Words," a lyrical attempt to own his past misdeeds (“I’ve made mistakes, stumbled“). The intro choice instead acted as a misplaced defense mechanism against any non-Beliebers present. He needn't have worried; there weren't any.

The show's staging delivered much of the showmanship. There were arresting visuals, smoke, fire, water, a couch. Bieber's dancers contorted their bodies, dangling from a makeshift ceiling, their movements ebbing and flowing with the rhythm of each track -- there were times when the concert felt the way a pop show of this magnitude should.

Bieber participated in some of the theatricality, too: He did two backflips on a hanging trampoline, engaged in some light Mr. Roboto-inspired armography, and held a microphone to his face to mimic singing when he mustered up the will to fake it.

But considering the ever-brightening glow of Bieber's star power and the endless expanse of his reach, you'd think he'd engage the crowd more, with even a base level of enthusiasm.

There was the occasional head-nod, the glimmer of a smile, his labored footwork. Bieber hit most of his marks with ease, but there was a disconnect there, too, like maybe he doesn't want any of this as badly as he used to. Like maybe he'd like to sleep awhile, instead.

Emerging from backstage at one point in his grey Purpose sweatpants, Justin soon splayed his body across the stage floor. "There's gonna be days to not do anything. I love those days," he said. It was the most believable line he delivered all night.

The Purpose Tour is a well-oiled machine by design, but cracks in its facade showed early on. After mistakenly skipping over the section of the stage show where he's supposed to perform the Ed Sheeran-penned "Love Yourself," he had to interact with the crowd while stagehands moved in to right his wrong. He then motioned to the uppermost nosebleeds telling them, off-script, "You know, when Jesus comes back you guys are the first to go."

Several songs later he flubbed again, delivering the right script at the wrong time: "Do you ever feel like sleeping all day? Oh...that's an intro for a different song, so I'm gonna come back to that later." And he did, for the speech's intended target — the heavy-handed "Life Is Worth Living."

Sleep was Bieber's unintended theme of the evening, and one could see how bad he wanted it whenever the cameras zoomed in on his glassy, dead, fish eyes.

From a sonic perspective, the evening was a success. While Bieber ignored the majority of his back catalog ("As Long As You Love Me," "Boyfriend" and "Baby" were the only pre-Purpose tracks performed), the new material was remixed and expertly translated to fit the vast expanse of an arena. Much of Purpose, it turns out, was meant to be heard live.

"Where Are U Now?" was the evening's first triumph, all bellowing synths and intricate staging. Purpose bonus tracks "Been You" and "Get Used To It" got their due diligence too, with tightly-choreographed routines highlighting their danceability. "Company" saw Bieber & Co. high above the stage on a suspended trampoline, while guest features from Halsey and Big Sean ("The Feeling" and "No Pressure," respectively) offered looming visual accompaniments, with pre-recorded videos of the artists integrated into the set. Even the cringeworthy "Children" made a case for itself live -- as long as Bieber's unsettling "What about the children!?" cries are ignored.

Mat Hayward, Getty Images

When Bieber did deign to sing without the aid of a backing track (less frequently than you might hope), he sounded good — great even, and that's the crux of the whole thing, isn't it? He can sing, dance and play drums, guitar and piano. He maintains that he appreciates his fans, overzealous and "draining" as they can be sometimes. He's proud, above all else, of his latest release. Still, it seems Bieber's been pushed well past exhaustion, and is now propped up solely by obligation. That reclaimed window of pre-show free time wasn't enough to reinvigorate him.

But the show moved forward to its choreographed end, and Bieber didn't stall things for a second. He may be going through the motions, but at least he's going through them.

"Sorry," the most infectious apology in Bieber's lengthy arsenal and quite possibly the best song of 2015, brought things to a triumphant close, as a geyser of water rushed down center stage. Bieber stood, stock-still, bathing in the massive flood, mic held firmly to his side, head cocked high to heaven. If the show must go on, he seemed to say, so be it.

See Photos From the Opening Night of Justin Bieber's Purpose Tour