FORT MYERS, FLA. -- It was a quiet evening with his wife, nothing special about it. Joe and Maddie Mauer had a handful of errands to run after the Twins’ spring workout that day, and a baby sitter was watching the girls. The couple decided to grab dinner on the way home, not at some fancy five-star bistro on the beach, but at a chain restaurant they passed on the highway.

Shortly after the Mauers left, their waitress took to Twitter to announce it. “Just served Joe Mauer of the Minnesota Twins!” she wrote. “He gave me a fat tip!”

The next morning, the Twins first baseman rolled his eyes when told about the tweet. “Glad I left enough, I guess,” Mauer said. “You never know who’s watching.”

Would he prefer that nobody did? Would he give up his fame, his status as one of Minnesota’s most recognizable icons, if he could just play baseball in anonymity? “Absolutely,” he said with a smile. “In a second.”

That’s the thing about Mauer: He just wants to be an Average, Everyday Joe.

Ready to hit

Tom Kelly has watched more baseball, critiqued more ballplayers than just about any Minnesotan alive. Yet even the longtime Twins manager still stops what he’s doing to watch Joe Mauer when he’s on deck.

When he’s at the plate, too, of course. But Kelly believes Mauer’s uniqueness emerges 25 feet from the batter’s box, before he ever sees a pitch. “I’ve always thought we should film Joe getting ready for his at-bats and show it to young players,” Kelly said. “He has a calm about him that’s pretty special. He always so quiet, always focused. Very confident, very deliberate. He gets more ready to hit than anyone I’ve seen.”

It’s not just in uniform, though. That calm, that serenity infuses Mauer’s entire life, from the modest, bland demeanor of his public image to a determined, protective persona his friends and family see. And it has come in handy over the past several months, as his baseball career and private life have each entered a new era, undergoing enormous, fundamental changes. Some have been difficult and disappointing, others ecstatic and blissful; none has visibly transformed him, or even ruffled his hair.

In fact, it’s fair to say just about everything has changed about Joe Mauer lately — except Joe Mauer.

“Everything that comes at him, he just takes it in stride. He’s always been that way,” said Jake Mauer Jr., Joe’s father. “It’s probably part of why he’s always been so good at sports. He doesn’t let things rattle him like most people. He seemed like a grown-up when he was 16.”

Never has that preternatural maturity undergone more stress tests, though, than over the past 15 months. Since just before Christmas 2012, the Twins’ homegrown MVP has married his sweetheart and moved his offseason residence back to Minnesota. He’s watched Justin Morneau, his closest friend in baseball, depart the Twins, leaving him as the final remaining link to the team’s decade of success. He delivered a statistically admirable yet oddly unsatisfying baseball season of his own, and endured a third straight bitter slog of a season as a team. He suffered a painful and frightening head injury, then reluctantly agreed to surrender the position that made him a star. Most of all, Mauer savored the ecstasy of witnessing the birth of his twin daughters, Maren and Emily, and withstood the misery of a concussion-induced haze that sometimes prevented him from being with them.

“Yeah, that was scary for a while,” Teresa Mauer said of her son’s nearly-three-month ordeal after being hit on the head in August by a foul ball, a condition that made him sensitive to the noise of a baby’s cry and the light of a baby’s bedroom. “You don’t know when it’s going to go away. And you hear stories about guys who, it never went away.”

That occurred to Mauer, too, since Morneau, as close as a brother when they were teammates, suffered similar symptoms for months. The fuzziness eventually waned, but Morneau’s career did, too, and that prospect disturbed Mauer.

“I’ve seen him go through it, but to actually feel it … ” Mauer said, contemplating the uncertainty that dogged him every time he had to squint in a normally lit room. “I would recall some of the things he would say, how he was feeling. [Now I’m] like, ‘Wow, he was hurting pretty good.’ ”

Mauer absorbed a different type of hurt, however, when Twins General Manager Terry Ryan met with him in November to deliver a command disguised as a prescription: No more catching. Suddenly, his major league persona was pulled out from under him, the position he had spent half his life mastering now off limits. He earned an MVP in 2009 as a catcher, made the All-Star team six times behind the plate. The Twins were paying him $184 million because he is worth more as a catcher than anything else.

He took some convincing.

Mauer would have preferred remaining at catcher, said assistant GM Rob Antony, but ultimately “Joe said, ‘OK, it’s good for the team and it’s probably good for me in the long haul.’ ”

The move became real in February, when Mauer reported to camp without his shin guards, chest protector and catcher’s mask. And even while he explains how he has embraced the change, it’s not hard to detect his mixed emotions.

“I came up a catcher, and it was kind of my identity back there. I’m definitely going to miss it — I do miss it,” Mauer said. “I miss calling a game, and working with the pitcher, and trying to do little things that most people don’t recognize but that have a huge impact on the game.”

But catching would mean risking another concussion, with the likelihood that each one could be progressively worse. Perhaps six months of fogginess instead of three, 139 games missed instead of 39. And even less time with his wife and daughters.

“I think that did it,” said Glen Perkins, Mauer’s teammate and fellow Minnesotan. “He’s got a family to think of.”

The Mauer twins

Now 8 months old, Emily and Maren Mauer weigh about 20 pounds apiece. Or just about perfect for an upper-body workout.

“He puts them in car seats, and carries them around like he’s weightlifting,” Teresa, grandmother to Joe’s first children, said, laughing. “I think he [considers] it part of his training. You never see him with just one.”

It has been enjoyable for his friends and family to watch him widen his list of priorities, too, from hitting and catching to bottles and diapers, all with his patented cheerful stoicism. Mauer made it easier for his siblings, cousins and in-laws to take part in raising the twins, too, by abandoning his normal habit of skipping Minnesota’s winters for his Florida bachelor pad. Mauer jokes that the decision was based on deepening his roster of baby sitters, but his parents believe it’s more about nesting.

“I think he realized it’s time to come back. Maddie’s family is in Minnesota, we’re all there, all his nieces and nephews and cousins are there,” Jake Mauer Jr. said. “When you’re young and single, where else would you be but in Florida? But now he’s thinking of other people, too.”

Thinking, raising, doting. The stuff most men turn to as they reach 30 years old, as Mauer did last June. He may have the wealth and the fame and the accomplishments, but those around him believe that Mauer sort of knew all along that more important stuff would come along.

“He’s always been a family man at his core, and now he’s got his own kids,’’ said Twins President Dave St. Peter. “That doesn’t change who he is, it reinforces it.”

It likely reinforces his instinct to shy away from public life, too, to minimize the intrusions that his profession, not to mention the modern social-media watchdog culture, makes on his family. But Mauer always has been even-keeled, compliant. He signs autographs, makes public appearances, represents his team. This July, he will be Minnesota’s ambassador to the All-Star Game, adding responsibilities as host to the burden of playing baseball.

“He’s been given a lot of attention, had a lot of demands placed upon him, and sometimes he gets a little tired of that,” Antony said. “But I don’t think he’s ever disrespectful to people or doesn’t treat people well. I wouldn’t expect that to ever change.”

No, because change is something that happens around Mauer, not to him. He’s getting older — “It’s a little weird being the old guy,” he admits — but doesn’t feel like he’s nearing any sort of a finale, not for a long time.

In fact, he feels like he’s just getting to first base.

Down the line

Lesson No. 1 at Tom Kelly’s school for converted first basemen involved the dress code.

Look at your uniform, the manager told his new star pupil. There is no armor around your legs, no padding on your chest. Forget your instincts about bracing for collisions, because contact is a bad idea for an infielder.

“He’s always been fearless, and probably still is. But now you don’t have the [catcher’s] gear on. So you’ve got to get out of the way,” said Kelly, who has played and taught the position for more than 40 years. “We’ve covered some things about keeping from straying into the basepath. Getting your arm out of the way, your wrist, your legs. Basic stuff, but it’s new to him.”

New and necessary, because the Twins, who haven’t gotten more than 107 games in the field from Mauer since 2008, are intent upon him staying healthy. Mauer has noted to anyone who will listen how much better his body feels, freed from all the squatting behind the plate.

“Believe me, he wants to do very well. That’s his personality, that’s why he’s as good as he is. He’ll work hard at it,” Kelly said. “If he doesn’t do very well, I’d be shocked.”

Mauer was shocked, he said, at how much he still had to learn after playing the position part-time for a couple of years. No longer just a break from his real job, first base is a test he intends to ace.

“I was talking to [converted Boston Red Sox catcher] Mike Napoli — ‘Yeah, it’s not as easy as people think, huh?’ ” Mauer said. “But that’s exciting. I love challenges. I love to learn new things about this game. I’m always trying to get better, always trying to pick things up and apply them. And now I have a pretty big thing to learn.”

And baseball can learn something more about Mauer, same as he ever was. “Once people get to know me, they realize I’m really not that cool. You know, ‘Oh, it’s just Joe,’ ” said the extraordinary ordinary man. “I like being that guy. I feel pretty normal at home, and I try to keep it that way.”