As 48 Hours Anchor Dan Rather reports, the answer lies with Thomas' mentor and agent, Elvin Bale, one of the greatest daredevils of his circus.
"People think I'm a different person, but I just go to my job and do my job," says Thomas.
"I'm not very different," he says. "I just get shot out of a cannon twice a day and three [times] on Saturday. Fifteen times a week."
His routine is quite familiar for Bale. His whole life was the circus, he says. Every two years, Ringling Brothers employed his services to build new death-defying acts: acts like the heel-catching trapeze act and the wheel of death. And of course the cannon.
His career ended abruptly in Hong Kong in 1987, though, when things went horribly wrong.
"I got shot out. I was at the top of my arc, and I looked down and I realized there was no way I was going to make that air bag," says Bale.
"They covered me over, and they said to my wife, 'Why don't you go back to the dressing room? There's nothing you can do,'" Bale adds.
But Bale just wasn't ready for his final bow.
Sean Thomas at work
For years, the cannon lay silent at Bale's home in Florida, until one day Thomas appeared, looking for a shot at the big time. That marked the beginning of a wonderful relationship.
"He almost became like a son," says Bale. "Because sometimes I want to hit him."
During Thomas' first season, Bale was never more than a phone call away.
"When I'm waiting for the shot to go off, I'm feeling the adrenaline," says Thomas. "I'm getting pumped up. I take a deep breath and hold my breath."
"Listen to the din, you know, the crowds," says Bale. "They're excited to be here. They're all talking about the tent and the tigers, the clowns and the elephants, and the human cannonball. Pretty soon, it'll all come together and start, and it'll be magic."
48 Hours caught up with Thomas this summer in Japan, where he astounded crowds with his cannon capability.
"Once you do it, it's hard to get away. You make good money and it's an opportunity to see Japan. It's in your blood. You're never gonna quit until you get too old," he says.
As for Bale, he has taken another human cannonball under his wing. Her name is Eli Valentino, kown as The Raven.
"I like scary things," she says. "I wanted to be the woman getting shot out of the cannon. It's like a thrill for me and I love to fly through the air."
"Once you are free of the barrel and you open your hands and you fly, this is amazing," Valentino says.
Bale declares. "Once she got it, she's great. I mean, you can seeÂ…she's perfect. She's really a perfect cannonball."