For many teenagers, their minds are preoccupied with an upcoming math exam or whether their crush likes them.
But Carson Kropfl has other things to think about — notably, his six-figure mini-skateboard business.
Carson pitched Locker Board on ABC's "Shark Tank" last year and now boasts Virgin Group founder Richard Branson as an investor. According to Carson, it's the first non-folding skateboard on the market that can fit inside a backpack and locker.
But Carson didn't set out to build a business.
In September 2016, as a preteen in San Clemente, California — an oceanside city in Orange County with a thriving skate and surf culture — Carson was frustrated when he couldn't fit his skateboard inside his new school locker.
So he decided to come up with a solution.
"I just love making my own stuff, making stuff unique," Carson, now 13, tells CNBC Make It. "And I think it's so fun to just be on the creative side, do my own thing.
"So I just thought, 'Let me make my own skateboard.'"
Carson, who'd recently gotten into working with wood with his dad, Keith, went around to local skateboard shops and collected used skateboard decks so he could fashion his own miniboard.
It took Carson five tries to get it right (including the time he screwed a piece of the board's hardware on backwards and didn't realize until he wiped out).
The key was the shape. At first, he built a small but typically shaped skateboard with rounded edges. His feet hung off the end when he tried to use it. So instead, "I made it kind of rectangular shaped," Carson explains. "I still have room for my feet, I could still do tricks, and it was still really fun to ride." It also made the board more stable.
The first Locker Board Carson created was 14 inches long, but ultimately he created a 17-inch skateboard after discovering it would fit in his locker if he angled it correctly. (A traditional skateboard is 33 inches.)
At first, Carson just used the board himself. But Carson is also a surfer, a hobby that can get expensive. So when his parents gave him a list of chores he had to do to earn an allowance that would pay for surf lessons, he had another idea.
"I've never been the best at cleaning my room, so I was like, hey, I just made this skateboard called Locker Board, maybe I should try selling it," he says.
Carson already knew his skateboard deck was a hit with the kids at school, so why not sell them? Carson began collecting more used decks from skate shops and cutting them down into miniboard decks to sell to his classmates.
"I'd put five in my backpack and pull them out at lunch and be like, 'These are $20 a board,'" Carson says. "And I'd sell them, and I saved up about $1,000."
But Carson wanted to offer complete skateboards. So that November, he used his $1,000 to buy trucks (the steering devices on the bottom of the board) and wheels, the two other components he needed to make a complete skateboard.
He enlisted the help of his mom, Carrie, who now handles the business component of Locker Board, to help him create a website to sell the skateboards. He and his parents also sold them at the local farmer's market and a local retailer, Jack's Surf Shop. Success was small but steady: By March 2017, he had sold about 100 to 150 skateboards.
But Locker Board isn't even Carson's first invention. When he was in first grade, he created Streetubez, a blue tarp contraption skateboarders can use to simulate a wave.
Not long after he invented it, Carson was on vacation with his family in the Sierra Mountains when he and his father were in the elevator with a man in a "Shark Tank" sweatshirt. Fans of the show, they asked if he had been a contestant. No, the man said, but he was an executive producer for the series.
Excited, Carson told the producer, Max Swedlow, he should have a spot in the Tank and showed him photos of Streetubez. Although Swedlow said Streetubez (which, at the time, consisted of just one prototype) was too small a business for the show, he gave Carson his contact information to keep in touch. (Swedlow did not return a request for comment.)
Carson did just that.
"For four years, every six months, I would update him on what's going on," Carson says. "When he found out about Locker Board, he said I was ready for 'Shark Tank.'"
At that point, in March 2017, Carson had made over 400 skateboards. Though he says he was only a little nervous about his television debut, his mom was "freaking out," he says. The night before filming, he practiced his pitch (asking for $60,000 in exchange for 15 percent equity) for four hours.
The hard work paid off. Carson's pitch was so compelling, three sharks fought to invest: Mark Cuban, Robert Herjavec and guest judge Richard Branson. Branson invested $65,000 for 20 percent of Locker Board, giving it a $325,000 valuation.
"I chose Richard Branson because he's actually Sir Richard Branson," Carson explains. "He's been knighted by the Queen of England. He also owns [dozens of] companies. He owns an island, he owns spaceships."
"And we had a connection; he told me I reminded him of himself when he first started his business."
Indeed, Branson tells CNBC Make It he did see a bit of himself in Carson.
"Carson's enthusiasm and passion for his business was what first caught my attention on 'Shark Tank,'" Branson says. "It was wonderful to see someone create a business from wanting to make people's lives better — and at such a young age!
"It reminded me so much of how I got my start as an entrepreneur," Branson tells CNBC Make It. "It's been delightful to watch Carson build his business and his personal brand."
Carson's episode aired on the Season 9 premiere of "Shark Tank" in October 2017, when Carson was 12. To celebrate, he had a watch party at Wahoo's Fish Tacos (founder of Wahoo's, Wing Lam, is a business advisor to Carson, and Wahoo's is a partner of Locker Board).
"I remember right when [the episode] was turning on, all these people were like 'Oh my gosh it's on, it's on!' And all the [restaurant] workers were trying to watch it too ... were telling everybody to be quiet ... it was just so crazy," he says.
Carson also remembers watching the number of people on his website jump from five to 1,500 in a matter of seconds, thanks to the show. Orders rolled in one after another, making Carson "pretty dang happy."
Branson's investment in Locker Board enabled Carson to bring on a skateboard manufacturer, PS Stix. Now the decks are made from 100 percent recycled wood from "blemish" boards, or boards that typically would be thrown away because of mistakes in the artwork. The manufacturer reshapes the blemished decks, sands out the blemishes and then applies Locker Board's artwork.
Locker Board currently offers four different skateboards: a 24-inch designed for the skate park for $128, a 17-inch designed for tricks for $98 and two different 17-inch boards designed for cruising, each for $116.
"I could have just gone to China or something and made a cheap, plastic skateboard, you know? But that's not my mission statement," Carson says. "My mission statement is to create cool, new sustainable products that inspire others to shred hard, dream hard and work hard. So I just want to keep it sustainable, and sustainable is better in the long run."
Since the show aired, Locker Board has grown over 300 percent, according to the company. The boards are now sold on its website, Amazon and at a few local retailers. Locker Board now has two patents and four trademarks and has done over $68,000 in lifetime revenue.
Along with Branson, Carson's also collaborating with Nike on a project. Though Carson can't reveal what it is just yet, he says he talks to Noah Murphy-Reinhertz, the head of sustainable innovation at Nike, once a week. In fact, he now considers him a mentor. For example, the pair recently discussed how Carson can make Streetubez sustainable by using recycled parachutes instead of tarps.
Of course, Carson's skate to the top hasn't been completely smooth.
"During those four years when I was kind of building my companies, I had to face through some hard stuff," Carson says. Jealous kids "ganged up on me at school, adults sent me nasty e-mails, competitors threatened me and my family, and random people on social media ripped me apart. All because I was doing something different," he remembers.
"But then I kind of realized to never give up."
Carson currently goes to school for two out of six periods each day but is home-schooled for the rest of his courses. His typical day is divided among schoolwork, work for Locker Board and surfing. His goal, he says, is to get a Locker Board in the backpack of every kid in America, and he has no intention of slowing down.
"I've learned basically three important lessons," Carson says. "To seize the moment, never give up and believe in yourself.
"I think every kid should have the opportunity to skateboard," he adds. "It really teaches you the lesson to never give up, because it can take you hours to land a new trick, but when you finally nail it, it's like the best feeling in the world."
Like this story? Like CNBC Make It on Facebook!