South Whidbey grad Mark Sargent has been known for many things. Once it was for homemade fireworks. Another time he was the digital pinball champion of the world.

Today, he is a leading figure of the Flat Earth movement.

That’s right, he believes the world is flat. He’s made a career out of the belief and is quite successful at it.

Sargent has his own weekly radio show. He is a published author. His YouTube page, which includes over 20 “Clues” videos, has nearly 40,000 subscribers and a whopping 8.4 million views. He’s been interviewed by journalists and producers more than a 100 times in the past two years, including a recent front page feature in the Denver Post.

Most recently, a Los Angeles documentary television crew traveled to South Whidbey to meet Sargent and then fly him to Oregon for live coverage of the eclipse.

The word you’re likely searching for is, “what?”

Another common one is, “really?” according to Sargent’s mother and Freeland resident Patty Sargent. At least that’s what her closest friends said when she told them about her son’s newfound success as a conspiracy theorist.

As for the man himself?

“I absolutely believe the world is flat,” he said.

Sargent, 49, says it with fervor and the knowing smile of a person who has seen the truth and must, with patience, reveal it to others.

He knows it because he can’t disprove it and because it feels right.

But let’s get to that in a moment. First, the answers to the questions everyone is asking.

Yes, he really believes the earth is a disk. People don’t fall off because they run into Antarctica; it’s not a continent at the South Pole but borders the known world like a fence. The public doesn’t investigate or fly over it because they can’t — it’s all part of The Antarctic Treaty of 1959, an agreement strictly enforced by the highest levels of government.

They’re in on it. NASA is fake, and so are its images of space and the cosmos. Man has never been to the moon, because it doesn’t exist as we know it. Neither do the sun or any of the other planets.

Boiled down, at the heart of the theory, Sargent believes mankind is lives in an enclosure.

Kept by whom, and for what reason, is another question.

“I don’t know,” he says, breaking eye contact with a Whidbey News Group reporter and, for a moment, revealing uncertainty.

Are we kittens, something to be protected, or scorpions that need watching, he wonders? All he knows is the world is a stage, and we’re all — most of us anyway — just unknowing actors.

If this sounds familiar, it’s because you’ve watched the 1998 film “The Truman Show.” It’s the story of a man who becomes enlightened when he learns his entire life has been lived inside a massive dome, which is nothing but a Hollywood set with him the star.

Sargent’s theory about the realities of earth are similar to the plot, as are themes taken from other films.

Movies and media have and continue to be a major influence in his life. He mentioned more than half a dozen titles over the course of a two-hour interview.

For example, most Flat Earthers never talk about their beliefs because “the first rule of flat club is you don’t talk about flat club” — a modified line from another 90s cult classic, “Fight Club.”

When he realized the “truth” two years ago, he said it was his “Jerry Maguire” moment.

But movies aren’t the only rudder that guided Sargent on a journey that took him from a job as a proprietary software consultant to a leading figure of a global conspiracy theory.

A big part it has to do with his personality.

“I’ve always been kinda eccentric anyway, so it wasn’t a huge stretch,” he said.

For starters, Sargent has long been intrigued with explosive ideas, some of them literal.

He was kicked out of Western Washington University for making his own fireworks. Prior to his interest in a flat earth, he investigated and believes in a host of other conspiracy theories: JFK wasn’t shot by a lone gunman, the moon landing was faked, Pearl Harbor and the Sept. 11 attacks were orchestrated by the government, etc.

Flat Earth he called the “last book on the shelf,” the one even he didn’t want to read. He saids he was as skeptical as anyone, and set out to disprove the conspiracy. He understands the frustration and sometimes anger people respond with when he talks about his conclusions.

“I was one of you,” he said.

Born and raised on the Whidbey Island, he grew up in a Christian household. His mother was a South Whidbey school teacher for over 30 years, and his father worked for Whidbey Telecom.

Sargent was an “A” and “B” student, was his class president, and served as president of his chapter of The Future Business Leaders of America. He went to state with his basketball team, and, in January 1995, was featured in The South Whidbey Record as digital pinball champion of the world.

Later, he got into video game testing, something he did as a career, before moving on to the software industry.

So why give it up to promote a theory the vast majority of people find ridiculous, to live a life that often leads to public mockery and trial? Like those in the “Matrix” movie series, most Flat Earthers have always felt something about the world just wasn’t quite right, Sargent said.

It may seem counterintuitive, but joining the club often comes as a relief because they can finally identify with other like-minded people.

For the first time, they’re not different and no longer alone.

It also provides answers to perhaps mankind’s greatest question of all, one pondered for millennia: Why are we here?

“I’m not going to lie to you, there’s religious overtones here,” Sargent said. “If it’s not God, it’s the closest thing we have to it.”

For many believers, that belief alone makes the ridicule that comes with the theory worth it. The angle of the Denver Post’s story focused on that aspect of the Flat Earth movement.

Sargent says it hasn’t been as difficult for him as others. He hasn’t lost friends, but admits most he associates with today are those who share his beliefs.

That includes his love life — he said he no longer dates “non-believers.”

And family is a mix. His sister, who lives and works on Whidbey, couldn’t be reached for comment, but isn’t a “member.” Some are open supporters and believers, others keep it from spouses.

And then there’s mom. While admittedly shocked when he first broke the news, it was hardly a surprise.

“He’s really been an out-of-the-box kinda kid,” Patty Sargent said. “Who wins a pinball championship?”

She also complained about the attention from her son’s fans. He regularly receives gifts, everything from Flat Earth models to a massive coffee table that weighs a “ton.”

Shirts, he gets them in the mail so often that he jokes he’ll never have to buy a T-shirt again.

Sargent no longer works a conventional job, working solely on his Flat Earth efforts. He lives off royalties. He declined to say exactly how much, said it is under $30,000 a year.

Patty Sargent is supportive. Increasingly supportive. In fact, she’s become a believer as well, though she admits she was apprehensive about “coming out” publicly — her son’s theories aren’t common knowledge on South Whidbey — and cringed to think what her teacher friends would say. But she mustered up her courage and revealed more.

Turns out she has a vein of skepticism herself, a rather large one.

“Do I think we’ve landed on the moon?” she asked. “I’ve never believed that.”

The two laughed together about how the knowledge might be received in their longtime community.

“This will be my opus or my tragedy, one or the other,” Mark Sargent said.

“And you’re going to take your mother down with you,” she said.