DEL MAR, San Diego County — Every summer for the past three years, Steve Kerr has left part of his heart in the Bay Area and come down here to the place he and wife, Margot, call home. The Golden State Warriors’ head man loves Northern California, but he is a son of the sun, a beach boy at heart.

Kerr is a serious coach — he has a pile of busted clipboards to prove it. But he’s also the guy who can laugh in the heat of battle, who will put a friendly hand on the shoulder of a ref, who demands that his players have fun. His personal vibe is in tune with San Diego, where people are serious about kicking back.

Kerr strolls into a restaurant that is a stone’s skip from the beach. He is wearing flip-flops, his feet and ankles are caked with sand. He is cleverly disguised as a surfer dude in a Cubs cap.

Not that he needs a disguise. It amuses Kerr that while he is known all over the world as the coach of the planet’s greatest basketball team, his fame hasn’t yet reached San Diego. When people here recognize Kerr, invariably they are tourists from the Bay Area.

At the restaurant’s reception desk, I ask the hostess if Steve Kerr has reserved a table. She smiles and says, “I don’t know him.”

Kerr laughs when he is told that.

“There you go,” he says. “I rest my case.”

Kerr doesn’t seek the spotlight, especially not in the offseason. He agreed to this exclusive interview because he recognizes the incredible interest the Warriors have created. And he knows there is great curiosity about his health.

Over lunch, Kerr — as always — is at ease and willing to take on just about any subject, from yoga to politics.

The good news: Kerr can still laugh. The laugh is important. It is a vital piece of his personality, it punctuates his speech and puts people around him at ease. For the past two years he has experienced chronic headaches in the wake of back surgery, and he laughs less often. But it’s still there.

The headaches caused him to sit out the first half of the 2015-16 season, and last season he stepped away from coaching for 11 games during the playoffs. While talking and lunching, he occasionally twists his neck, a sign of his still-present discomfort. This is not Kerr’s favorite topic, but: How’s his health?

“It’s all right, it’s all right,” Kerr, 51, says with a shrug. “I’d love to say that I’m all better, but not the case. I’m feeling better, having a good summer, relaxing. But it’s just been an ongoing thing now for two years.”

So there’s improvement?

“Yeah, yeah, I’ve definitely gotten better, I’ve made some improvement. But I still feel like there’s improvement to make.”

How confident is he that he’ll be able to coach all season?

“I fully expect to coach all year,” Kerr says in a no-nonsense tone. “That’s my expectation. And for many years to come.”

He says that getting back to the demands and pressures of the job when training camp opens won’t be a problem.

“No, I don’t look at it that way,” Kerr says. “I enjoy what I do; I don’t look at it like a grind and pressure. I’m looking forward to getting back in the gym.”

Doctors are not able to tell Kerr when or if his headaches will stop. Talking about it doesn’t help, so he says, simply, “I’m very proud of what we’ve accomplished, and I love being part of something special. In a perfect world, I will get some relief from the pain I’ve felt, so I can enjoy it more.”

Kerr and Margot and their three children moved to San Diego 15 years ago when he retired as a player. They love the place, they fit right in. Steve surfs and hangs at the beach. Some of his coaching ideas come when he is dragging his feet through the sand. He can’t play golf now, but he does go to a course to putt and chip, and to visit buddies.

This offseason, Steve and Margot went to Hawaii, and to Newport, R.I., for the wedding of former Warrior Harrison Barnes.

Kerr practices yoga every other day, the hot kind (Bikram). He’s been doing that since he retired. He likes the physical part of yoga, as well as the spiritual element.

“For sure it’s a meditative thing,” Kerr says. “I like the movement that goes with the meditation. I’m not great at the sit-still-and-meditate.”

No coach ever stops coaching, even in the offseason. Kerr says he spends at minimum a couple of hours a day on Warriors business.

“I’m on the phone, talking to (general manager) Bob Myers, talking to our coaches and to different people. Writing down thoughts, putting together plans for our coaching retreat (before training camp). It might be just something that pops into my head, where I just stop and write something down. But I’m not Jon Gruden (famous workaholic), I’m not waking up at five in the morning and going to the film room (laugh).”

Kerr and Myers have formed a tight friendship, a brotherhood. They brainstorm daily.

“We talk about players, talk about roles,” Kerr says, leaning back in his chair and resting an elbow on the railing. The table affords a view of the Del Mar race track and the Pacific Ocean surf. Easy place to relax. “We talked a lot about Nick Young and (Omri) Casspi before we signed those guys. Talked a lot about our center position. Bob and I talk every day, kind of the first thing in the morning we check in with each other, usually talk for a half hour. We’re really close. He just got back from a great vacation, in Italy.”

To outsiders, Myers can seem obsessed with his job, but Kerr sees another side — an intense competitor who has a very clear world perspective.

“He’s right there with (Spurs coach) Gregg Popovich and (former NBA coach) Phil Jackson, in terms of people who are at a really high level in the NBA but who just get it, who understand what makes people tick. I think that’s one of the reasons we (the Warriors) have the culture that we do, is that Bob and I kind of see things in a similar fashion.”

Kerr came to the Warriors three seasons ago with no coaching experience, and was successful from the start. He says that one key to acceptance by the players was that he and his assistants gave full credit to the players and previous coaching staff for the major improvement the team had already made. He told them, “We’re not coming to change things, we’re coming in to help take the next step.”

The players nodded and went to work. The next step turned out to be an NBA championship.

“The players see through all the b.s.,” Kerr says, as the waiter presents his plate of sauteed-fish tacos. “And to me, that’s what NBA coaching’s all about. College is a little different, you can have the authoritarian coach, but the NBA game’s about the players. The coaches are the stewards. The players gotta know you’re in charge, and that you know what you’re talking about, but in the end it’s about them.”

Kerr gets a lot of enjoyment following the off-season adventures of his players, on the news and on Twitter. He texts his guys — “I try to leave ’em alone, but just to say hi.” He closely followed Stephen Curry’s recent foray into professional golf.

“That was amazing,” Kerr says. “Seventy-four? Two days in a row? The second day was even more impressive — afternoon, with the wind, and a lot of PGA guys talking some s—.” He laughs.

Kerr says his experience as player taught him that it’s important for players to get away from the game, especially after a long playoff run, and the Warriors have made three consecutive runs to the Finals.

“That’s a long, long haul,” he says. The toll on the players is “more emotional than physical. You kind of get used to flying around and staying in hotels and all that. But the two-month grind of the playoffs, where you’re having to get up for every game, and then relive that game for a couple days, and get picked apart, and the stress that goes with that. Do that over and over and over again, it wears you out.”

If Kerr’s kick-back nature syncs well with Southern California, his political bent is a perfect fit for the Bay Area. His Twitter feed is interesting. A lot of retweets of things he finds inspiring. You will notice that he leans liberal.

The morning of the interview, Kerr had retweeted video of a speech given by New Orleans Mayor Mitch Laundieu, last May, when the city took down a statue of Robert E. Lee.

“It’s one of the most incredible speeches I’ve ever seen,” Kerr says, shaking his head. “I’d read about it, then this morning I was online and I watched him, it blew me away — so inspiring, so beautiful, so brilliant.”

On occasion last season, Kerr went public with his thoughts on the political scene, his dismay and disgust at what was happening, before and after the presidential election. It seems apparent that Kerr feels an obligation to use his public platform to occasionally express his non-basketball opinions.

“Yeah, I do,” he says. “I do think when you have a platform, it’s important to speak out when you feel it’s necessary. That’s something I do from time to time. I don’t like to grab the spotlight, but I’m asked questions. Almost every day there’s a press conference, and people ask. So I answer.”

Last season, Kerr expressed support for Colin Kaepernick’s national anthem protest. Kerr stresses that he believes the protests then and now (Michael Bennett of the Seahawks and Marshawn Lynch of the Raiders have protested this season) are not intended to disrespect the military; rather, they honor the military, the people who fought for American freedom, including the right to peaceful protest. Kerr fully supports the right of his players to speak out and to protest.

“You’ll hear from our guys,” Kerr says. “You’ll ask, they’ll give you opinions. Those opinions won’t always be liked, but they’ll be honest, nonviolent opinions, and very thoughtful.”

Kerr says the Warriors held a team meeting early last season to discuss Kaepernick and possible protests by Warriors. (No NBA player protested.) The players were told that the organization would not object to protests, but would appreciate a heads-up because, Kerr says, “It would be a big story, and we want to make sure we have each other’s backs and understand each other’s viewpoint.”

Controversy looms over the traditional White House visit by the NBA championship team. It’s possible the Warriors won’t be invited. If invited, it’s unlikely they would go. The team will kick around that subject early in training camp.

That’s ahead. For now, Kerr observes the world, drags his toes through the warm sand, and looks forward to getting back to the the Bay Area, his guys and the gym.

Scott Ostler is a San Francisco Chronicle columnist. Email: sostler@sfchronicle.com Twitter: @scottostler

Read more: Part two of The Chronicle’s exclusive interview with Warriors head coach Steve Kerr, featuring a deeper look at the upcoming season for the defending champions.