Sunday is the 10-year anniversary of his perfect game against the Braves in Atlanta and the D-backs will honor him in a pregame ceremony.
If you ask him about his night of perfection 10 years later, well, don't expect him to regale you with a play-by-play account.
That's because after he finished his media obligations that night and showered, he had already moved on and was looking toward getting ready for his next start.
"That's the one thing that I've noticed since I've stopped playing baseball is that I'm getting older, because time just doesn't stop," Johnson told MLB.com. "It just kept going after I retired and life went on. I've stayed busy, I don't feel older, but obviously I'm getting older. Next thing you know we're having a 10-year anniversary for the World Series and now a 10-year anniversary for my perfect game. It just doesn't seem that long ago that I threw that perfect game. Although it does feel like 10 years as far as me remembering details of it, because I don't remember many of the details of the game."
A lot of times athletes have a hard time moving on with their lives after retirement, especially the ones like Johnson, who dominated their sport.
NBA legend Michael Jordan has struggled since he retired to find an outlet for his competiveness and he has not had much success as an executive. Others get into broadcasting or need to be around their sport and remind others of their accomplishments.
Johnson has taken a different tack, pouring his heart, soul and creativity into what has long been a passion for him -- photography.
Since his retirement following the 2009 season, Johnson has traveled the globe taking pictures and helping out the USO. Baseball, his job for so many years, has faded into the background.
"I'm a different person now," Johnson said. "I do like to reflect on my career a little bit when people come up and ask about it. Over the last five years since I've retired I've traveled with the USO and I've traveled the world with my wife. I'll run into people that recognize me and will bring up a moment that they remember."
Johnson has attacked his photography, much as he did pitching, with maximum effort and intensity. It is not just a hobby for him.
Johnson made a brief appearance at Spring Training for the D-backs in 2013 and was going to do so again this past year before his schedule would not allow it.
One of the many things he could teach younger players is the value of always looking for the next challenge.
In retirement, he does that in photography, and during his career he would come to Spring Training even after winning a Cy Young Award and a World Series MVP and declare that he had spent the offseason working to improve some facet of his game.
One year it might be holding runners or fielding his position. Another might be spent working on bunting so that he might not have to be pinch-hit for and could stay in for another inning.
"As soon as you can realize your deficiencies and you work on them and try to bring those things up a little bit then you get better," Johnson said. "And you want to keep getting better at the things you already do well. So it was never-ending process and that's what I enjoyed about the ride. I never looked back, I never dwelled on the good games, but always took stuff from the bad ones and always took multiple things from my season and looked at those things."
Recently Johnson was going through the office in his Phoenix-area home and he came across pitching charts from his games during his latter days with the Mariners and his early years with the D-backs.
Though some mistakenly thought that Johnson relied simply on overpowering hitters with an upper-90s fastball and devastating slider, there was much thought that went into each outing. Johnson would hang onto those pitching charts and study sequences he used to get hitters out.
Rather than make him complacent, Johnson's success -- he won 303 games in his career and ranks second on the all-time strikeout list with 4,875 strikeouts -- drove him harder because he knew what was expected of him and what he expected from himself.
"Obviously in the moment I would dwell on bad games," Johnson said. "I felt like I let the fans and the team down because obviously I still had the responsibility and everybody was assuming that there was going to be a certain type of game pitched -- whether it was a dominant game or not, it was going to be a victory. That was what came along with what I established in my career."
Johnson, who last played in 2009, will be on the 2015 Hall of Fame ballot and is expected to get in on the first ballot.