He'll retire in January after 45 years in baseball, including the last 22 as the greatest Commissioner the sport has ever had.
At times, memories come in waves.
"What a journey it has been," he said. "It's a long way from 1970. Who would have thought all this would happen?"
One of the saddest days of his life was when his beloved Braves packed up and left Milwaukee for Atlanta after the 1965 season. He immediately began to work to bring the sport back to the city, and he did it the old-fashioned way.
He worked the phones, knocked on doors, cajoled, counseled, pleaded for help with the project. One of his first important meetings came after he drove from Milwaukee to nearby Madison to sit across from Oscar Mayer.
Yes, that Oscar Mayer.
"I didn't know him and was so nervous," Selig said. "I was 29 or 30 at the time. He turned out to be a lovely human being and loved baseball. When we were done, he came around his desk, shook my hand and said, 'I'm in. I look forward to being your partner.'"
The Brewers played their first game on April 7, 1970. They lost to the Angels, 12-0.
"Andy Messersmith pitched a great game," Selig said. "That was the only time I didn't care whether we won or lost."
"I can't tell you how happy I was to have baseball back in Milwaukee," he said. "I'm feeling so good about it. But after the game, I ran into this guy who said, 'Well, you said you wanted baseball in the worst way. Looks like that's what you've got.'"
Forty-four years later, Selig laughs again as he remembers the moment.
OK, let's push the pause button to understand why Selig cared so much. This is the heart of the matter.
As Commissioner, he has led a breathtaking transformation of the sport. Make no mistake about this part of the deal. All the good things that have happened to Major League Baseball these last 20 years have happened largely because of Selig's leadership and vision.
He took over the sport at a time when it was in trouble on an assortment of levels. Now, look at it. There's financial prosperity for both players and owners. There's 19 years of labor peace, competitive balance, record-setting attendance, a new generation of ballparks, Interleague Play, Wild Card playoff berths and a host of other changes.
He also was the guiding light for a little endeavor called Major League Baseball Advanced Media, which has transformed the way fans consume games, highlights, news and analysis.
"One of the great success stories in the history of American business," Selig said proudly.
Selig had a hand in all of it, and he did it by walking a fine line between respecting the rich history of the game while embracing innovation and change.
Strip all of that stuff away, though, and there's something simpler at work here.
"I regard myself as a baseball man at heart," he said.
Indeed, he is that.
He still watches games, still loves the sport. He second-guesses managers and umpires, still admires the great players. He appreciates Derek Jeter's dignity, marvels at Mike Trout's skills and is impressed by Joe Maddon's genius.
Almost each night, he settles into his favorite chair at home, turns on his screens of choice and flips from game to game.
He fell in love with the sport growing up in Milwaukee. His parents, especially his mother, a great fan, regularly took him to Wrigley Field. From her, he learned to appreciate the nuances of the game, the stars, ballparks, all of it. She also took him to New York, for a tour of the ballparks in the 1950s.
"Well, she wanted to see the museums," Selig said, "but it was a baseball trip, too. That's when I first saw Joe DiMaggio. Can you imagine the impression that made?"
As owner of the Brewers, he loved the competition. OK, he loved the competition some of the time.
"Remember how that door would swing open?" he asked.
When he was angry, doors would slam at County Stadium. Sometimes in the press box. Sometimes in the box where his general managers, Harry Dalton and Sal Bando, sat.
"I can still remember the look on their faces when I'd walk in there," he said. "Look, I could be horrendous when we were playing poorly."
When Dalton brought George Bamberger to Milwaukee to interview for the Brewers' managerial job, Selig began the conversation by saying, "I understand you want to manage our club."
"Your club?" Bamberger snapped. "Bunch of losers."
Selig hired him on the spot.
Selig loved his players, too. They were his guys, especially two of them -- Paul Molitor and Robin Yount -- he saw last weekend in Cooperstown.
"It's the people," he said. "It's a people business. If you're lucky enough to be around people like that, you feel awfully blessed."
And there was the final weekend of the 1982 season. The Brewers blew a four-game lead in the final week of the season.
On the last day of the season, in Baltimore, they were tied with the Orioles. The Brewers won that day to clinch the American League East, and when it ended, Orioles owner Edward Bennett Williams, a notoriously competitive man himself, threw his arms around Selig.
"You know I hate losing," he whispered. "But if I had to lose to someone, I'm glad it's to you, Buddy."
After the game, someone examined the seat where Selig had sat and found a couple dozen half-smoked tiny cigars beneath his seat.
He gave up smoking years ago, and when he turns 80 today, he'll begin the day with his 2,210th consecutive day on an exercise bike.
"It relaxes me," he said. "Sometimes, I don't want to get up, but I feel great when I'm done."
He keeps a grueling schedule, arriving in his office by 10 most mornings and sometimes staying until dark. He's on the phone almost constantly with owners, executives and a kitchen cabinet of sorts from which he solicits advice. This group includes trainers, doctors, general managers and an assortment of current and former players.
One of the things that made this year's Hall of Fame induction ceremony so special was that it included Joe Torre, a longtime friend.
"I've known Joe since he was 15 years old," Selig said. "His brother, Frank, and I are very good friends. He's just a wonderful man."
Selig will be in his office as usual on his 80th and then have dinner after work with his wife, Sue. He'll attend a birthday party in his honor over the weekend. But his 80th will be a work day. It's still the thing that drives him and excites him, the thing that has helped keep him going hard.
But he speaks enthusiastically about what's ahead, the teaching and writing and all the rest.
"I think writing the book is going to be like a full-time job for at least awhile," he said.
He has had a front-row seat to the evolution of both a sport and a country. He'll write of the places he has been and the things he has seen. He'll write about old friends like Hank Aaron, whom he met in 1958 and has remained close to ever since.
Selig knows there'll be other opportunities apart from the book and the teaching. He's excited about those, too. He won't retire, at least not in the way a lot of people think of retirement. He simply isn't geared that way.
He sees this next chapter of his life as a time to think and reflect, a time to share some of what he has learned and to attempt to tell his wonderful story.
There are people inside the sport who simply can't comprehend that he's actually retiring. For 44 years, he has been a source of wisdom and voice of reason in virtually every important decision.
To them, the idea that he won't be around as a sounding board, counselor, friend and guiding light is an idea they're still attempting to get their mind around. He will leave the sport incomprehensibly better than he found it, and baseball's growth and innovation will be his enduring legacy.
For that, there is no real way to express the gratitude of all he has done. Plenty of people will try just the same. This he understands and appreciates.
Happy Birthday, Commissioner.