I promised Greg Chism I wouldn’t reveal anything about where he lives because there are people out there obsessed with him, convinced he’s a monster. What I can say is that my GPS took me from my hotel somewhere in the American Midwest to an upscale, spacious home with well-kept lawns. Greg was waiting for me in his driveway, an unassuming, friendly, ordinary father of two in his mid-50s, wearing a Van Halen sweatshirt and blue jeans.

His smile faded as I jumped out of my car. He had agreed to meet me, but now he looked uneasy. He had never given an interview about the events that overtook his life in 2016 and 2017.

Greg took me inside and showed me his den — a shrine to his two great loves, Hot Wheels and Tom Petty. He led me through to his home office. We sat at his desk, and I turned on my recorder.

It was 10 a.m. He had bottled up his story for seven years, and we didn’t stop talking until his younger daughter, Annabelle, arrived home from school at 4 p.m., beginning with his childhood in Granite City, Ill. “It was a factory town,” Greg said. “I was destined to be at one. But in my lifetime, all but one of the factories closed. My father lost his longtime job making car frames and hot-water heaters when the plant moved to Mexico.” Like many men of his generation, Greg was left adrift, with few of the structures that guided his parents and grandparents.

From there, his life became more difficult. At 17, he was working at Taco Bell when he felt his heart racing. He collapsed, unconscious.

He was diagnosed with atrial flutter. After that came multiple open-heart surgeries, which left him with scars and, at 18, six figures of medical debt; his marriage fell apart suddenly when he was 39, leaving him a single father with full custody of two children under 2. But he managed to find free babysitting through a local church, which allowed him to earn money mowing lawns.

And then, one night in 2010, he had his Damascus moment. “I was watching some random You Tube video,” he said. “This guy was cycling through Australia. He pulled over and pointed at a koala or something, and then he made a speech. He talked about all the negatives in his life.” He had struggled, he told the camera, and the viewers beyond it.

He had lived on the streets and been in jail. “But then he said: ‘Whatever, I’m out here having a great day, riding my bike and making a You Tube video. You can make a You Tube video! You’ve got a story. Share it! Don’t hold yourselves back! Make a You Tube video and change your life!’” Greg paused. “It was very inspiring, dude.

He hit me hard.” Greg began cautiously. His first video was just him reading out loud a newspaper article about a Florida woman who had accidentally burned down America’s fifth‑oldest tree by smoking meth underneath it. After he read it, he said to the camera, “Isn’t that crazy?” “The video got 10 or 12 views,” Greg told me, “and a comment: ‘You look like you’ve been smoking meth.’” It was in reference to Greg’s teeth.

They overlapped significantly. “They were the wildest‑looking teeth,” Greg said. “We didn’t get dental work done when we were kids because we didn’t have any money.” But the comment motivated Greg. “I decided to get my teeth fixed. I signed up for adult braces. I had to get a $6,000 line of credit.

After that I started making videos about my adult‑braces journey. I learned about tags — ‘adult braces,’ ‘adult braces cost’ — and the next thing I knew, maybe 50 people a week who were looking for adult braces found me. I had regulars.

They’d be saying, ‘I’m on Week 3’ and ‘We’re so proud of you.’” Soon, Greg’s regular viewers looked past his teeth to the lawn mowers behind him. “People started to comment, ‘Why do you have four lawn mowers?’ I’d reply, ‘I do lawn care.’ They were like: ‘Dude, you do lawn care? Do a lawn care vlog!’ I was like, ‘Dude, nobody wants to see a lawn care vlog!’ But they were hounding me. ‘Nobody’s vlogging about lawn care! Do a lawn care vlog!’ So I went ahead and made a ‘Day...