By the third day, Mechalle Brown's concern had dissolved into firm resolve, so she flung open the door to her son's bedroom, snapped up the shades, cranked the windows and announced, "We're not doing this anymore."

Jaylen Brown, blinking from the sudden daylight, sighed heavily. He had sequestered himself in darkness and solitude for the better part of the weekend, emerging only when his mother coaxed him out with culinary bribes: jambalaya pasta for dinner, French toast for breakfast. Anything, she would later admit, to stir him from his funk.

But now Mechalle had seen enough.

"Today is a school day," she informed her son, "and you are going."

Jaylen groaned, dragged himself out of bed and plodded to the bathroom to shower.

It was March 2014, and Brown was a top national basketball prospect at Wheeler High School in Marietta, Georgia, starring for a powerhouse team heavily favored to win the state championship. But Tift County -- donning T-shirts declaring, "No Buckets!" -- had jumped Wheeler, forcing 13 first-half turnovers. Brown led his team in scoring with 17 points but fouled out with three minutes to play and slumped on the bench as his singular goal for the past three seasons -- bring home the title -- unraveled in front of him.

He glanced into the bathroom mirror as he replayed the events of the past 48 hours yet again. Brown blanched from a wave of nausea, then leaned over and vomited into the sink.

"I had attached my life to basketball so closely that it made me physically ill," Brown says now.

A painful high school experience helped Jaylen Brown realize he cared about basketball "too much." AP Photo/Charles Krupa

Brown would not attend a single day of school that week. His physical and mental devastation over the loss prompted a discourse with his mother, who spelled out her expectations. Disappointment, she explained, is part of life, and you must use it to grow stronger. It's fine to be passionate about basketball, but it cannot matter more than family, education, your health.

This is your mantra, Mechalle advised her teenage son: Basketball is not who you are. It's what you do.

"It was a turning point," Mechalle says. "Jaylen needed to understand life was going to throw a lot of things at you, but you can't let them make or break you."

Four years later, Jaylen Brown, now 21, generates as many headlines for his posture as a basketball Renaissance man as he does for becoming the youngest Boston Celtics player in history to score 30 points in a playoff game, which he did Tuesday night in a rousing win over the Milwaukee Bucks.

Brown's diverse portfolio -- public forums at Harvard, challenging a child prodigy to a chess match -- leads to inevitable skepticism that seems to dog well-rounded professional athletes: Does he care enough about the game?

He does. He just can't afford to care too much.

"I don't ever want to experience that again," Brown says. "Looking back, I definitely suffered a [bout of] depression. But people don't want to hear about that. It freaks them out.

"I wish people were more comfortable talking about it. But they aren't, so we keep it to ourselves. We're supposed to be 'a man,' we're supposed to bottle everything up.

"I came out of it realizing, 'OK, this basketball thing, it meant a little too much.'"

The ongoing task has been to find balance in a game that has come to define him, on a team that has come to depend on him, in a league in which every high and every low is dissected and accentuated in a high-profile manner. It has been a useful exercise; in fact, it might very well have saved Brown's young Celtics career.

Jaylen Brown learned quickly that if he didn't know how to play defense, he wouldn't see the floor. Adam Glanzman/Getty Images

The offensive development of Jaylen Brown has become a trendy talking point now that his back-to-back career-high playoff performances have staked the Celtics a 2-0 first-round series lead over the Bucks. Even before that, Toronto coach Dwane Casey likened Brown to Scottie Pippen. The wildly premature Kobe Bryant comparisons are flattering, too, but Brown knows the drill: "Brad Stevens is a defensive coach. If I want any shot at getting on the floor, I gotta know what I'm doing defensively."

That has been a work in progress. Boston's defensive rotations require alert, precise, collaborative participation. As a rookie last season, Brown had to learn on the fly how to identify various NBA actions and anticipate where the next threat was coming from. It was both confounding and confusing, and he executed it with mixed results.

"You have to see two cuts ahead," Stevens explains. "If you are the fifth defender on a play, you won't be the fifth defender for long. Most 19-year-olds aren't ready for that. It's a difficult adjustment that becomes more difficult on the biggest stage, where there's no place to hide."

"Everybody talks about development and enhancement. Nobody talks about rocky times and how you handle those. To me, that's a bigger launching pad." Brad Stevens

Brown's length, quickness and basketball acumen spurred Stevens to challenge his young talent to become an elite defender. His 0.829 points per play rating last season, per Synergy Sports, ranked him better than all but 14 percent of the league's defenders, but, Stevens reminded him, he could be better. Much better.

"We realize how Jaylen defends is a big part of us," his coach says.

Last season, Brown's defensive quantitative shot-making (qSM) was minus-2.7, according to ESPN Stats & Information research. The qSM stat is a measure of how shooters differ from their expected effective field goal percentage. Brown's mark last season was 27th overall. This season, he ranks seventh overall in the NBA among players who defended at least 500 shots, with a minus-4.5 qSM, a notable improvement.

"It's night and day [from last season]," veteran Al Horford says. "I look at him on film all the time. Before, we would tell him, 'Jaylen, you can't get back cut out of the corner.' He would walk into the game and -- boom! -- back cut out of the corner right away."

When Brown did grasp the rotations, the results were startling. Stevens was so impressed with one particular sequence, seen here from a Jan. 7, 2017, game against New Orleans, he spliced it into the team's film session. Brown hedges to help on superstar Anthony Davis, then sprints to the corner to contest E'Twaun Moore's 3-point offering by leaping into the air and extending his arm like an erector set.

Opponents often delight in exposing first-year players in isolation, yet Brown held his own last season. He gave up just 0.9 points per chance in isos, good for 66th in the league, per ESPN Stats & Info research. (Those numbers have improved to 0.79 points/chance on isos this season for a 17th-best league mark.)

Brown craved opportunities to guard elite scorers. He exhibited pockets of success against heavyweights such as LeBron James and Klay Thompson and got torched (along with the rest of the Celtics team) by Devin Booker. Usually, vets dish some smack as they blow by rookies, but, Brown said, "Nobody knew who I was, so they didn't bother. The only people who talked trash to me were my own teammates."

Last season's Celtics roster was stockpiled with underpaid veterans who stalked the hallways of the practice facility with chips the size of Ferris wheels on their shoulders. The uncommon demeanor and quiet confidence of a blue-chip prospect such as Brown, whose mellow visage masks his true competitiveness, occasionally landed him in the crosshairs of his teammates. There was the celebrated squabble with Marcus Smart last March during a win over the Timberwolves, when Brown freelanced his way to the hoop on a drive (and missed). The next time down the floor, an animated Smart scolded him, "Wait on the play!" Isaiah Thomas was notorious for riding Brown hard for his defensive lapses -- even though IT's own defensive rating was among the worst in the league.

"Jaylen didn't know the [defensive] rotations," former Celtic Gerald Green says. "The guys would get on him. I pulled Jaylen aside and told him, 'They just want you to be better.' To his credit, he didn't say, 'F--- this, I don't want to be everyone's punching bag.' Instead, he said, 'OK, I understand.'"

"Last year was definitely a different group" Horford concedes. "We had some guys out here scrapping, grinding but also doing a lot of talking. No one really pulled Jaylen under their wing. But Jaylen observed, he listened, and I think he learned a lot."

Teammates have grown accustomed to Brown's unusual dalliances and his tendency to carve his own path. During All-Star Weekend, while his NBA peers were trying to score tickets for Michael Jordan's Bel Air bash, Brown was hitting up Fortune 500 representatives to attend his tech summit. He explores these avenues without apologies -- "Basketball is what I do, not who I am" -- and with the understanding it has the potential to set him apart from the mainstream vibe of the locker room.

"It's hard when you are so young to take those chances,'' Horford says. "I don't know if I would have been able to do it at his age. I admire Jaylen. For most of us, it takes years to become comfortable in your own skin. Jaylen is already there.''

Brown bided his time during his rookie season, aching for more minutes he felt certain he deserved. When Avery Bradley strained his Achilles tendon and missed 16 games in February 2017, Brown was plugged into the starting lineup. Instead of harassing second-unit players, Brown was suddenly chasing around CJ McCollum and JJ Redick. "We threw him to the wolves,'' Stevens says.

Yet the Celtics went 13-3 with Brown in the lineup, and the rookie's confidence soared.

"When I got the opportunity to start, I felt like I had earned something,'' Brown says. "I was mistaken.''

When Bradley returned, he resumed his starting role while Brown reluctantly retreated back to the bench. Defense is Boston's identity, and as Brown's rookie regular season came to a close, he detected a pattern in the final month. If he missed a shot, he was encouraged to shoot another. But if he missed a defensive assignment, his stint on the floor ended abruptly.

When the 2017 playoffs began, Brown poised himself for a coming-out party. Instead, he languished on the bench during a first-round series against the Chicago Bulls, averaging just 5.8 minutes a game.

"When we threw him in there for that first game, the intensity -- that's what people don't realize -- it's so heightened," Horford explains. "There's no time for 'my bad' on defense. You have to be locked in. Jaylen can be a little laid-back at times, and, mentally, I just don't think he was where he needed to be in that series."

Jaylen Brown's hard work paid off in Game 7 of the Celtics' second-round series against the Wizards last year. CJ Gunther/EPA

There were also other factors at work. During the regular season, Jae Crowder was the most frequent defender on Bulls star Jimmy Butler, but he was ineffective, so Stevens switched Bradley onto Butler, making him indispensable on the floor and cutting into Brown's time.

After falling behind 2-0 in the series, Stevens made another move: replacing Amir Johnson in the starting lineup with the veteran Green, who rewarded his coach's faith in him by chipping in with eight points in Game 3, then exploding for 18 points and seven boards in Game 4. Green gobbled up the rest of Brown's minutes, leaving the rookie as the odd man out.

Stevens, sensing Brown's despair, initiated an impromptu meeting with him before Game 6 at the team hotel in Chicago.

"I knew it was hard for Jaylen," Stevens says. "I'm sure he was pissed at me. At the same, he just kept working."

"I've seen young guys break down. They're cruising along, playing great, then their minutes get funky and they fall apart. Some of them never recover. That didn't happen with Jaylen." Gerald Green

Stevens stressed to Brown it wasn't so much his errors, but the groove of the new lineup that was keeping him sidelined. He urged his young forward to stay ready for the next series. "After we were done," Steven says, "I remember thinking, 'Man, when this guy gets back in, he's going to be a monster.'"

Brown knew everyone was watching to see how he reacted to his reduced role -- including his ever-vigilant mom -- so he channeled his disappointment into a resolve to pounce on the next opportunity.

"There was no room for any kind of negativity," Brown explains. "No time for emotional temper tantrums. No one has tolerance for that, especially on a winning team.

"It would have been easy for Brad to say, 'Oh, he's going to act like that?' The next thing you know, I would have been at the end of the bench for good."

As he navigated this new, unfamiliar basketball role, he discovered an unlikely mentor in the very man who hijacked his minutes -- Gerald Green. The well-traveled veteran tugged at his teammate's shoulders and told him, "You can be special. But you gotta grab that chance. It starts here. In practice." No more lapses, Green stressed. No more wasted possessions. And -- most of all -- no hanging your head.

"I've seen young guys break down in those situations," Green says. "They're cruising along, playing great, then their minutes get funky and they fall apart. Some of them never recover.

"That didn't happen with Jaylen."

It couldn't. Not again. Use disappointment to make you stronger.

You can be special.

"I know Gerald thinks, 'Oh, that rookie probably doesn't remember me,' but I'll never forget what he said to me -- what he did for me," Brown says.

The Celtics played Washington in the second round, and Stevens gave his rookie another shot, incrementally increasing his time until Brown logged 19 critical minutes in Game 7. And when Thomas was shut down in the conference finals due to a hip injury, Brown's minutes -- and his production -- blossomed. He hasn't looked back, emerging in these young playoffs as one of the breakout stars.

"Everybody talks about development and enhancement," Stevens says. "Nobody talks about rocky times and how you handle those. To me, that's a bigger launching pad."

As the defensive plaudits begin to trickle in, the Celtics staff keeps its budding, two-way talent grounded with data to remind Brown he still needs to sharpen his off-the-ball defensive skills. Last season, he gave up 0.85 points per chance when defending the cutter on an off-ball screen, according to ESPN Stats & Info research. This season, that number worsened slightly to 0.87 points per chance. Stevens eagerly awaits the day Brown transitions from knowing what is coming and reacting to the play to knowing what is coming and instinctively being there.

"Because of his ability," Stevens says, "we hold him to a very high standard."

There is no higher standard than what Jaylen Brown envisions for himself.

"I'm emotionally and physically ready," he says, "for anything."