When he was about 15 years old, Jaylen Brown decided to grow out his hair. He was just a kid at the time at a large high school in Marietta, Georgia, and on his way to becoming a 5-star recruit. A few years later, he'd move west to suit up for Cal. The year after that he'd be drafted third overall by the Boston Celtics, where he'd spend the next three seasons evolving from feisty rookie into playoff starter.

Through all the changes, there remained one constant in his life: the perfectly groomed flat top perched upon his otherwise-shaved head. As Brown's image grew, so did his hair, both in literal stature and what it represented. It became nearly impossible to think of Brown and not picture the hair. It was his thing.

But in late September last year, he decided it was time for a change. He'd recently returned from a trip to China, where he had suited up in the FIBA World Cup for Team USA. He was excited for the tournament. The previous season had worn him down, and he was giddy about the opportunity to rack up some successes, to remember what it felt like to have fun on the court.

"I wanted to win that so badly," he says. "It would have been good for me." Brown played well, but the team did not, losing twice and failing to qualify for the medal round. "I was devastated," Brown says. He spent the night after the first defeat to France awake in his hotel room, replaying the game in his head.

A few weeks after returning to Boston, Brown called up his barber, put on a gown and set up a chair inside a shower stall. Soon after, and for the first time in seven years, the top of his head was nearly bald. The pictures were posted on social media. Brown's phone blew up. Jokes filled his screen. Isaiah Thomas, Brown's former Celtics teammate, tweeted, "He took the microphone off his head lol." One friend told Brown it looked like someone had turned his head upside down. That line, four months later, still arouses a chuckle. But he's also clear that the decision to cut his hair was about more than generating a few laughs.

"I wanted to forget about last year, and that was a representation of the new energy, the new vibe I was looking for," he says. "People, a lot of times, identified me by my hair, and that was a part of the things I'm trying to get away from.

"I think people put you in a box, based on what they've seen from you, maybe the first time they watched you. I wanted to give people a whole new idea of who I am and what I'm about."

Spend even a little time with Brown and you quickly learn he's not the sort of person who blindly accepts things.

"He can be a bit headstrong," says former NBA All-Star and current G League President Shareef Abdur-Rahim, who has known and advised Brown for years. He means it as a compliment. For example, he says, when Brown was at Cal he wanted to take a graduate-level course called Cultural Studies of Sport in Education. But the professor teaching had never accepted a freshman before, and he thought the course load would be too much. He told Brown no "about five times," Abdur-Rahim recalls. "But Jaylen kept pushing and pushing. He said, 'You can't tell me I can't take a class.' And he was right." Brown convinced the school's dean to grant him access. He submitted a 23-page paper as a final project to pass the class.

In this case, on a January afternoon in an office at the Celtics' practice facility, Brown is offered the chance to talk about all the work he put in over the summer, a gift most professional athletes would run with. But he isn't particularly interested in discussing the thousands of offseason jumpers he hoisted or the countless hours he spent honing his handle by pounding the ball into a gym floor, at least not in a way where his performance this season gets attributed to that work. In his view, focusing on all that sweat would create a forest for the trees type of thing.

"To be honest, I've worked like that every summer," he says. "Everybody thinks I made some drastic change this summer. That's the narrative: that I did that, and that's the reason why I'm playing so much better."

Brian Babineau/Getty Images

Eighteen months ago, it was assumed Brown was on the verge of stardom. He was a 2016 No. 3 pick, just 21 and coming off one of the most impressive playoff stretches seen from someone his age. He'd helped the undermanned Celtics knock off the Bucks, upset the Sixers and take the LeBron James-led Cavaliers to seven games in the Eastern Conference Finals. His 18 points per game were impressive, but more promising were the myriad clutch shots he drilled, the way he seemed to thrive under the same spotlight that has seen so many others wilt.

But growth often isn't linear; life is more of a one-step-forward-two-steps-back type of journey. The Celtics entered last season as favorites to win the East, but they disappointed. And Brown, in a way, came to symbolize the team's stumbles. No leap was made. Instead, he regressed. "I dealt with a lot of anxiety and self-doubt," he says.

That's all disappeared this season. The 20.0 points, 6.9 rebounds and 2.3 assists he's averaging per game are all career highs (and major upticks from the 13.0 points, 4.2 rebounds and 1.4 assists he averaged last season). So is the 39.5 percent he's shooting from deep. He's doing all that while playing All-NBA-level defense. He could be in line for an All-Star nod, the first of his career, and is one of the primary reasons the Celtics have vaulted back up toward the top of the Eastern Conference standings.

The reason for his renaissance, in his view, is simple. And it has nothing to do with all his offseason work.

"Sometimes you're as good as the role you're in," Brown says. He's in a new one, and both he and the Celtics are thriving, although the path there wasn't smooth.

You could see it on his face last year. Frustration, yes, but also withdrawal. Brown had entered the season, "thinking that, you know, I'm going to be an integral part of the offense, be one of the main guys." He'd just helped carry the Celtics to within one game of the NBA Finals, "and I was just as good as anyone on that floor." But Boston's playoff run had come with Kyrie Irving and Gordon Hayward sidelined with injuries, meaning the follow-up campaign would require the reintroduction of two ball-handling All-Stars into the ecosystem, and, in Irving—who'd bolt for Brooklyn in the summer—a teammate seemingly playing out the season with one foot out the door. Chaos was inevitable.

"It's tough when you got a lot of guys that can go, that can do a lot of things with the basketball," Celtics guard Marcus Smart says. "It makes it tough to get into a rhythm. Last year was different for all of us."

Brown seemed most affected. His role within the offense diminished—especially in the season's first two months—and his minutes dropped from 30.7 to 25.9 per game. The tweaks were enough to send Brown into a tailspin.

"I kind of got pushed to the side, and that kind of messed with my confidence a little bit," he says. "Not only did I start not believing in myself that much, but I started overthinking, and that's when anxiety and stuff came in. It took me a while to get out of that."

The low point came in mid-November, during a desultory 98-86 home loss to the Utah Jazz. Brown played 25 minutes, and he made just one of his nine shots. He doesn't remember what exactly about that night set him off. But he says: "I was like almost to the point where I was fed up. You can go back and watch that game. You can probably see it on my face." He remembers at one point Jazz star Donovan Mitchell asking him if he was all right.

Michael Dwyer/Associated Press

"And I couldn't even say like, 'I'm good, bro.' I couldn't even give him one of those." Celtics President of Basketball Operations Danny Ainge noticed Brown's frustration too and approached him later that night. "I told him I was fine even though I wasn't," Brown says. "I remember that game was where I was like at the point of no return."

He's asked what that means.

"I was just fed up; that was it," he says. "I was just done. I just didn't want to…" He catches himself and trails off. "Whatever. I was done."

Brown can't quite pinpoint exactly when his turnaround began. He does know how it began, though: with a decision to "stop listening to what anybody had to say." He's not talking about critics or fans or #haters. Or, well, he is, but others too.

"Coaching staff. Front office. Everything. I literally just stopped caring what they had to say, and I just played basketball, what I've been doing my entire life," he says. "Like, I told myself that no matter what [Celtics head coach] Brad [Stevens] and no matter what Danny and no matter what anybody has to say, I'm going to just play basketball, and that's it. It was that simple. I needed to stop looking over my shoulder because I might get subbed out and stop thinking that much during the game. It was like, 'Fuck that, I'm going to just play and let the chips fall. I had to give myself my confidence back, and things like that, and remind myself of who I was and what I brought to this game and what I possibly could do."

Brown believes that everything in life happens for a reason, that every action has an equal and opposite reaction, that the gains he's made this year wouldn't be possible without the frustrations from last.

"It gave me a different perspective, it gave me more motivation, it gave me more drive, more focus, more attention to detail," he says. "It gave me things I needed. To be honest, last year was necessary. I mean it may sound like I'm complaining, but I'm actually happy that last year happened, because when you make mistakes, or you're embarrassed that things don't necessarily go your way, that's where the most growth happens. Some of the habits that you build to cope teach you a lot about yourself, so it was like a great personal growth year for me, not just on the floor but off."

He's reluctant to reveal much more. "Can we go to the next question?" he asks. But later he drops his guard, just a bit. Not about what he learned about himself but about how he learned it. At one point last season, his grandfather gave him a book on astrology. Brown couldn't put it down. The words, the lessons, they all spoke to him.

"Sometimes people get lost and forget who they are and what they bring to the table and their mission and purpose—I had to be reminded of mine," he says. "The aggressiveness I come with, that I don't back down from challenges, the fight that's inside of me, the passion—things that necessarily can't be measured but that you have, and I had to be reminded of all that."

Brown played better after the All-Star break last season, but the Celtics bowed out in the playoffs' second round. Soon after he met with Stevens and Ainge for exit meetings. Both, Brown says, "kind of apologized, like, for the role and the kind of things they put me through and how everything transpired."

(Stevens says he doesn't recall "every part of every individual meeting, nor would I share that. But I do remember saying this was not the year that any of us had hoped for.")

Adam Glanzman/Getty Images

A little more than five months later, on the second-to-last weekend in October, Brown's agent, Jason Glushon, flew into Boston to meet with the Celtics. This—having an agent represent him at the bargaining table—was something new for Brown. He'd represented himself during his predraft process and only hired an agent a few weeks earlier. But now he was due for a rookie extension, one that could garner him a nine-figure deal, and he was looking for some professional help.

Glushon and Ainge spent the weekend negotiating. On Oct. 21, they announced they had agreed to a four-year, $115 million extension. "That was a unanimous decision," Stevens says. "What Jaylen has done, as a young player in the role he's been in, on the winning team he's been on, there are not a lot of comparables. We want him to be here for a long time." It was the first rookie-scale extension the Celtics had handed out since signing Rajon Rondo to one back in 2009.

"That meant a lot," Brown says. He adds, however, that signing the deal "definitely wasn't the easiest decision. It wasn't as easy as people think. I had a lot of inner battles." Again, he doesn't want to reveal too much. Only that: "Anytime you make a decision that affects your future, you gotta do your due diligence. This is the only time as a player I have this ability to think about myself. But ultimately I made the right decision."

Brown has always wanted to be thought of as more. More than just a defensive player, more than a role player, more than just "an athlete who had potential to maybe be OK on offense but not really that skilled." He'd devoted his life to perfecting a craft and wanted to be recognized for his achievements, to be freed from his box. The extension helped some, though part of Brown believes that "people still think that I'm Jaylen from my rookie year." He hopes soon that's no longer the case. Understanding that just might be the key to understanding him.

Nothing's falling. It's a Thursday in Philadelphia, the second night of a back-to-back, and both Brown and the Celtics are laboring. Brown springs open for a three—and it rims out. He slices into the lane—and misfires on a floater. He cuts backdoor—and his layup caroms off the backboard. It's been like this for a few games now, his worst—and first—cold stretch of the season.

And yet, all the new skills, the ones he's so adamant about not discussing, are on display. In years past, left-handed finishes from Brown were so rare that he’d celebrate each one by pointing to Celtics video coordinator Matt Reynolds; now they're routine. He can stop and pop from any spot on the court. He navigates tight quarters with his handle instead of being stuck driving north to south. He fires crosscourt passes off the bounce.

"His growth as a playmaker from when he came into the league to now is unbelievable," says Micah Shrewsberry, a former Celtics assistant now coaching at Purdue. The upgrades have allowed Brown to thrive in his new, beefed up role. He's second on the Celtics in minutes per game (33.4, 7.5 more than he averaged last season) and has simultaneously upped his efficiency in nearly every offensive category.

The Celtics fall 109-98. Brown finishes with six points on 2-of-12 shooting, and afterward Stevens is asked about his struggles. "He's fine, I'm not going to overreact to anything," he says. "He's had a great year." Brown makes clear he's not concerned, either. "Some easy shots that I normally make, for the last two to three games they've gone in and out for whatever reason," he tells reporters. Post-shower, his nearly shaved head glistens under the camera lights. There's not a trace of discontent in his voice.

Yaron Weitzman covers the NBA for Bleacher Report and is the author of the upcoming book, TANKING TO THE TOP: The Philadelphia 76ers and the Most Audacious Process in the History of Professional Sports, available for preorder now. Follow Yaron on Twitter, @YaronWeitzman.