School’s out for the summer, and Papa is on his way to the final pickup.

Joe Namath pulls his Cadillac Escalade into the parking lot, snakes around behind the school and joins a line of cars waiting for the children to emerge after a half day. One of the most celebrated athletes of the past 60 years, now a suburban grandpa surrounded by a world of humdrum, recognizes a familiar face and lowers his window.

“Did I tell you how classy it was that you offered up your No. 12?” a school official asks Namath, referring to the old quarterback’s willingness to unretire his New York Jets number as an enticement for future Hall of Fame quarterback Aaron Rodgers to join the team.

“Oh, man,” Namath replies in an aw-shucks kind of way.

“That was very classy,” the friendly man says.

“We want to win; the fans want to win,” Namath says of his gesture, ultimately declined by the newly acquired Rodgers.

Just then, Namath’s 12-year-old granddaughter, Jemma, hops into the back seat, and they’re off. He senses she’s sad because sixth grade is complete and she will be off to a new school in the fall, so he tries to brighten her mood by asking about her classes. She perks up instantly, mentioning a lesson on the Fibonacci sequence in algebra and a discussion on “To Kill a Mockingbird.” She’s carrying a trophy, won in a school debate tournament.

“Good going,” Namath says, smiling as he checks out the hardware in the rearview mirror.

By now, they’re cruising up Route A1A on Florida’s east coast, past private golf courses and luxury communities. This is a familiar route for Namath, who picks up Jemma on most days and attends her activities. Just recently, she played the Queen of Hearts in the school production of “Alice in Wonderland” — and Namath was in the audience for two shows on the same day.

Broadway Joe is now a happy homebody, a doting grandfather of six, enjoying simple pleasures. His mind is sharp and his football-ravaged body, rebuilt with two knee replacements, two hip replacements and one shoulder replacement, feels pretty damn good, all things considered.

Decades removed from his famously fast life, Namath considers himself lucky in so many ways. Lucky to have his health. Lucky to be surrounded by loved ones.

Lucky he didn’t drink himself to an early grave.

JOE NAMATH TURNS 80 on Wednesday. Imagine that.

The long-haired provocateur from the 1960s and 1970s, who toggled between football and showbiz after guaranteeing victory and delivering one of the greatest upsets in sports history in Super Bowl III, is now an octogenarian. The flamboyant party boy who once said he liked his women blonde and his Johnny Walker red, who made movies and dated starlets and filled autumn afternoons with majestic spirals, is enjoying a peaceful, sober life on the Loxahatchee River in the village of Tequesta.

Namath lives in a sprawling ranch on the banks of the river, swims laps in his 41-foot backyard pool and works the elliptical machine in his exercise room, where his most cherished photographs adorn the walls — pictures of him with former coaches Bear Bryant and Weeb Ewbank, Hall of Fame quarterbacks Johnny Unitas and Joe Montana, and legendary Yankees center fielder Joe DiMaggio. He plays golf and enjoys boating; he has two docked in his backyard.

He watches his diet, tries to take a 20-minute nap every day (a tip from his old friend, late comedian Bob Hope) and believes in transcendental meditation. He learned it from author Bob Oates, who wrote a book with TM guru Maharishi Mahesh Yogi.

Namath gave up booze 20 years ago; now he sips water from a 24-ounce plastic tumbler — a “Joe Namath Foundation” bottle with images of him in his Jets and University of Alabama uniforms. The bottle goes with him everywhere; he doesn’t leave home without it.

Clean living. It hasn’t always been this way.

“When I lived in Manhattan a long time ago, I had this vision of two guardian angels,” he says. “I’m on a street corner and on my right shoulder — a guardian angel. On my left shoulder — a guardian angel. And they’ve got long, white beards.”

He pauses.

“They’ve been looking after me,” Namath says, smiling. “And I’ve been wearing them out.”

Namath’s life — from Beaver Falls, Pennsylvania, to the treasure coast of Florida — has been 80 years of adventure.

As a kid, he remembers he and a friend hung from a high railroad trestle to avoid an oncoming train overhead. At Alabama, he says he hit a wet spot on a highway, flipped a car and walked away with just a gash on his forehead. (He still has a small scar.) Later, in his 30s, Namath’s car went into a full spin because of an ice patch on a Beaver Falls bridge, coming perilously close to the guardrail and a several-hundred-foot drop.

None of those incidents were fueled by alcohol, he says. Namath says he wasn’t a big drinker in high school or college, though he recalls one time in high school when he drank a bottle of wine on his way to a class trip at an amusement park and woke up in a shoe-shine chair at the park, not knowing how he got there.

Eventually, the drinking escalated. He acknowledges he was on a path to destruction after his playing days.

“That’s right, you thought you were bulletproof,” he says. “Driving and drinking. I’d be doing theater in San Bernardino, California, and driving to Los Angeles regularly. Before I left the dressing room, I had a bottle of wine. … By the grace of God, I didn’t kill somebody.”

Another time, Namath — as an active player — went off the road and down an embankment while driving home from a youth football camp in Vermont. He wound up upside down in the car, so disoriented from the alcohol and the car flip that he couldn’t understand why the window went up when he attempted to roll it down. This was in the pre-electric window days.

He walked away, unscathed.

Namath, married for the first and only time in 1984, gave up drinking for a long period. His oldest daughter, Jessica, 37, says she can’t recall her father ever using alcohol during her childhood. The marriage ended in divorce in 2000, triggering an emotional spiral for Namath.

He hit rock bottom on Dec. 20, 2003, with the infamous sideline interview with ESPN’s Suzy Kolber. During a prime-time Jets game, an inebriated Namath tried to kiss her on live TV. Embarrassed and distraught, he apologized the next day to Kolber, recognizing he had a problem.

He says he hasn’t had a drink since then.

“After the Suzy incident, I knew I needed help,” Namath says. “I wanted to go get help and I did. I went to a facility and got some training, got some education. I used an excuse, going through a divorce. Literally, that’s what I learned.

“I started drinking again because I didn’t give a damn anymore. It was a painful kind of thing. [My daughters] were out in California at that time. It was a blessing in disguise. Maybe things could’ve been worse if we didn’t go through that, I really don’t know. But I know it was a great education.”

The 20-year anniversary of his sobriety approaches, a milestone that appears to surprise him. Honestly, he says, it seems longer than that.

Instead of the Broadway Joe lifestyle, Namath has settled into Ordinary Joe.

“If Joe would’ve kept drinking, it would’ve killed him,” says his oldest friend, Linwood Alford, 79, who grew up across the street from him in Beaver Falls. “Once he realized what was most important in this lifetime — God and family — that’s when the leaf was turned.”

Alford has known Namath longer than anyone. While he applauds his friend’s sobriety, he doesn’t believe it required a radical approach. As he explains, “Joe hasn’t done a lot of changing. I think he just enhanced a lot of the things that were buried — or embedded in him — at any early age.”

At an end-of-the-school-year lunch with Jemma, at a waterside restaurant he co-owns, Namath orders a nonalcoholic beer to go with grilled shrimp on a bed of greens. He doesn’t brag about his sobriety. No, he’s humbled by it.

“I don’t take a bit of pride in it,” he says. “I’m not proud, I’m thankful. I know how heinous or evil the stuff can be sometimes.”

Inside the restaurant — Lucky Shuck, a picturesque spot that overlooks the Jupiter Inlet and lighthouse — there’s a nod to Namath’s partying past.

Displayed on the wall is a wooden oar that says Bachelors III, the name of the controversial Manhattan nightclub he owned in the late 1960s. He was forced to sell his stake in the club at behest of the NFL, which didn’t want one of its star players associating with what it perceived as unsavory clientele. At first he refused to sell, going so far as to announce his retirement before relenting a few months later.

As much as he cherishes the present, Namath can’t escape his past. He embraces nearly all of it. He was a gifted passer who, despite wobbly knees, projected a swashbuckling aura on the gridiron. He lifted the upstart Jets to a 16-7 win over the Baltimore Colts in Super Bowl III in 1969 — still the high-water mark for the franchise. His immense popularity was one of the driving forces of the NFL-AFL merger in 1970.

Outside Lucky Shuck, Namath is recognized at the valet by a group of senior citizens, who ask for a group photo. He happily obliges.

“I spent many days in Shea Stadium watching you throw the football,” one of the men says.

Cool never gets old.

NAMATH’S KITCHEN IS part art studio, part shrine to his two daughters and six grandchildren.

The wooden table is covered with brightly colored markers, sheets of papers, drawings and a coloring book called “Doodle Dog and Sketchy Cat.” The materials belong to John, 6, who loves drawing for his Papa. Nearby is Emerson, 2, who scoots around on a red tricycle. John, Emerson and Jemma live next door with their mom, Jessica. Namath’s youngest daughter, Olivia, lives in California with her three kids.

The kitchen wall is covered with pictures of the entire Namath gang, including shots with Santa Claus and the Easter Bunny. The only reference to Joe or his legendary career is a Namath bobblehead, tucked away on a shelf. The faces on the wall are his Hall of Famers.

“He doesn’t miss much, this Papa Bear,” Jessica says. “He’s there for almost everything.”

Namath has gone from chauffeured to chauffeur, driving his grandkids to their various activities. Former teammate John Schmitt, Namath’s center in Super Bowl III, calls him “the world’s best babysitter.”

“One time I called him and said, ‘This isn’t Broadway Joe I’m calling, it’s Diaper Joe,'” Schmitt says with a big laugh.

Namath, the son of a steel mill worker who made $6,000 a year (about $75,000 in today’s dollars), loves his life. He played a sport that routinely spits out broken bodies and altered minds, but he’s nourished by love and a handful of old-school health tips he says have sustained him. Call them life lessons, picked up on his travels.

He works out 25 to 30 minutes a day about 20 days per month — he tracks it on a calendar — because of advice he received as a young man from the late Dr. James Nicholas, formerly the Jets’ orthopedist. Keep the heartbeat above a normal rate for at least 20 minutes a day, Nicholas told him, outlining a post-career regimen.

Namath has an exercise room, which includes a trainer’s table and a cervical-traction contraption that hangs from a door, but he prefers to get his exercise in the pool. During his final season, with the Los Angeles Rams in 1977, he couldn’t run because his surgically repaired knees were too painful, so the team’s athletic trainer suggested he do his cardio work at the pool in Long Beach High School. He fell in love with the water. These days, he wears resistance gloves while swimming laps.

It was during that year in Los Angeles when he learned the importance of eliminating salt from his diet. Lunching at the home of the late Carroll Rosenbloom, Namath was scolded by the Rams’ owner for using too much salt on his food. Mind you, he loved salt so much that he carried his own salt shaker as a kid and used it on everything from lemon to watermelon. Suffice it to say the salt shaker days are gone, although he might sprinkle a little on his movie theater popcorn.

During his time with the Jets, Namath was fascinated by teammate Dave Herman’s habit of ending every shower with a minute or so of cold water. He adopted the practice, finding it exhilarating for the body and mind. He has been doing it ever since.

“There’s something to the cold,” Namath says. “I believe in the cold.”

He also believes hyperbaric oxygen therapy saved him from the sinister effects of brain trauma, a scourge for many NFL old-timers.

Concerned about the “handful” of concussions he suffered as a player, and alarmed by the suicides of NFL veterans Dave Duerson and Junior Seau, Namath took a proactive approach to brain health about a decade ago. He participated in 120 treatments, or “dives,” at the Jupiter Medical Center.

“They’ve been looking after me. And I’ve been wearing them out.” Joe Namath on his “guardian angels”

Though hyperbaric oxygen therapy has limited approval by the FDA, Namath swears by it, saying his before-and-after brain scans showed marked improvement. His memory remains sharp, as he can recall in vivid detail events that occurred more than 70 years ago.

“It has helped me big-time,” he says of the therapy.

He thinks back to his early 20s, when he met retired boxing legend Joe Louis at Caesars Palace in Las Vegas. Namath calls it “one of the thrills of my life,” but it was a bittersweet moment because he recalls how Louis — in his 50s — spoke so slowly, presumably because of countless blows to the head.

“Kind of like Muhammad got,” says Namath, remembering the great Ali, whom he considered a friend.

The old quarterback pauses, pensively. You can tell his mind’s eye sees something from long ago, something that makes him smile.

NAMATH STARTS ON the defensive side of the ball.

“Sample is gone. Hudson is gone. Grantham is gone,” he says, naming Johnny Sample, Jim Hudson and Larry Grantham — all starters on the Jets’ 1968 Super Bowl III-winning team.

Continuing the macabre list, Namath works his way through the entire defense and then the offense. All told, no fewer than 19 of the 45 players on that legendary team have died.

Namath, still vibrant, has lived a charmed life. Sure, his thumb aches a little, probably the result of long-ago wrist surgery. His quadriceps burn if he climbs too many steps, but some perspective, please: The man is 80 years old.

“I’m lucky,” he says. “I honest to God know that. I believe that. I’ve been very fortunate.”

He doesn’t live with too many regrets. He wishes he had put more effort into his acting career, which includes at least 12 film credits, countless TV appearances and stage performances, most notably an off-Broadway production of “Damn Yankees.” He never had formal training, saying he didn’t give the profession the respect it deserves. That gnaws at him.

Then there’s his personal life.

“Regrets? Yeah, there are regrets. I wish your mother and I were together for eternity,” he says, glancing at Jessica. “But people change, things change.”

Not everything, though.

Namath hasn’t forgotten his roots. In fact, he still has the suitcase he took to college, when he left Beaver Falls for the first time. It’s proudly displayed on a shelf in his exercise room. He went to Tuscaloosa, Alabama, with that tiny suitcase — it has a “Roll Crimson Tide” sticker — and a $5 bill.

He returned a star.

“That name — Namath — still means a lot to a lot of people,” says Schmitt, his old teammate and close friend. “He’s a quiet king.”

In many ways, Namath still plays the role of quarterback. The great ones make those around them better, and he has done that with his loved ones. His granddaughter, Jemma, says Papa is her role model. At the same time, they elevate him. They have made his simpler, quieter life more rewarding than his previous life as Broadway Joe.

On a recent day, old No. 12 is standing on his front porch, playing with Zoie, a collie/shepherd mix from the local rescue shelter. Namath calls the dog one of the best receivers he has ever had, and he’s ready to prove it.

Forty-six years removed from his last NFL pass, he takes a Frisbee, cocks that famous right arm — with his new right shoulder — and flings it about 15 yards. It’s not one of those famous Namath bombs from yesteryear — let’s call it an intermediate seam route — but here, in the warm Florida sun, surrounded by family, he connects with Zoie: a fantastic running grab.

Another completion for Namath, who flashes that 1960s smile.

“I have a comfortable life,” he says. “I just wish it could be longer.”