(Editor’s note: This is Part VI in a seven-part series on the life and career of reigning Masters champion Dustin Johnson. Check back to Golfweek.com each day for the next part of the story.)

The brilliance of Dustin Johnson is his uncluttered mind.

While many fellow pros can go on and on about course management and others can talk endlessly about the complex principles of the golf swing, Johnson’s simplistic approach to life and putting the golf ball in the hole does just fine.

He isn’t about to sit down with the Mad Scientist, Bryson DeChambeau, and converse about the relationship between mass and velocity or do a deep dive on air density and local slope adjustment. And he doesn’t have much to say about the psychology of handling the game’s mind-numbing disturbances.

But because of his unwavering and carefree demeanor, a few infamous gaffes over the years on the golf course and his distant appearance during press conferences – where he often responds to long-winded questions with brief frankness – many tend to question his intelligence.

He has served as a punchline for followers on Twitter, been disrespected by the media at times and even disrespected by a few of his colleagues. Thus, despite winning a U.S. Open and last November’s Masters, collecting 22 other PGA Tour titles as well as a FedEx Cup, and reaching No. 1 in the world, his mind is rarely credited as a strength.

Well, as the English idiom goes, don’t judge a book by its cover.

“People don’t think he’s the smartest guy in the room and I think it’s because he’s got the southern drawl and he kind of talks slow, but that’s just how he talks and if it makes him sound maybe not the smartest, then so be it,” said 2007 U.S. Amateur champion Colt Knost, who roomed with Johnson the first year they turned pro. “He might not be book smart but he’s smart. And he’s like Rain Man when it comes to his golf IQ. I’ll bet you he can go through and tell you every shot he hit last year on the PGA Tour.

“He knows what’s going on, he knows how to manage his game now as good as anybody, he knows what he’s looking for in his equipment and he knows a lot about the golf swing even though he doesn’t let on that he does.

“Sounds pretty smart to me.”

Johnson just shrugged when asked if he’s bothered by the unflattering perception that he isn’t the sharpest tool in the box.

“I don’t know. Don’t really care about what others think,” he said.

Others, however, do care.

“He isn’t stupid. He’s sly like a fox,” said swing coach Butch Harmon, who started working with Johnson in 2009. “He gives a lot of those short answers because he doesn’t want you to bother him. To me, that makes him pretty smart. Now, does he have a lot of book smarts? I don’t know. And he can say some pretty crazy things at times, but he is not dumb.

“He understands his game and he understands what he’s good at and he understands what to do in the heat of the battle. He’s matured golf-wise and he’s become an incredibly intelligent player. That was one of Tiger’s great strengths – he knew when to be conservative. DJ has come to understand that.”

David Winkle, Johnson’s longtime agent, brought up the time six years ago when TaylorMade brought together their heavy hitters including Johnson, Jason Day, Justin Rose and Sergio Garcia for a few days of photo and video shoots. There also was a psychological profile examination with 144 questions.

“They wanted to get into the mind of a champion,” Winkle said. “And the expert who was analyzing the responses said there was one guy who has an innate ability to go into a cocoon of concentration like nothing he has ever seen.

“And it turned out to be Dustin’s profile. He gets into depths of concentration at times where he turns it on and turns it off, whether he’s ordering fast food or coming down the last hole of the Masters.”

Johnson’s state of mind certainly played into his record-smashing victory in the 2020 Masters. He dialed back his aggression when needed, trusted his top-flight precision and didn’t buckle in the final round when his lead nearly vanished and another tragic ending – such as his three-putt from 12 feet on the 72nd hole of the 2015 U.S. Open at Chambers Bay that cost him a chance at the title – seemed imminent.

“I think other than Jack and Tiger he has one of the greatest golf minds in competitive history,” said Claude Harmon, Johnson’s regular swing coach and son of Butch Harmon. “When he missed that putt at Chambers Bay and was walking off the green in ’15, and I would have told you all that would have happened from that point onward to here, would you have believed it? The scars are too deep, he’s never going to come back from that, all that.

“He’s just a very unique golfer. If you could design a golfer, you’d design him; no memory, just freak athlete, and we’re seeing an incredible amount of maturity from the last time that he won a major.”

Four-time major champion Rory McIlroy was equally impressed. McIlroy said he thinks Johnson has one of the best attitudes toward golf in the history of the game.

“And when he wants to engage with you and have a proper conversation about whatever topic it is, he can have it,” McIlroy said. “He just would rather not have it with you guys (media). That’s basically what it is. He saves that for his inner circle and the people he trusts and the people that he likes.

“When you are friends with him and you spend a lot of time with him, he’s much more engaging than a lot of people think.

“And he’s basically done everything there is to do in the game, and he’s done that by basically changing his game after turning pro. That’s a huge compliment. Not a lot of people can do that.”