Charles Robinson, a 22-year-old from Sussex, England, was just 19 when he founded his first company.

He first contemplated launching a business after moving to the U.K. capital to study philosophy at University College London—an institution that, despite its prestige, failed to inspire him.

“I never wanted to be an entrepreneur,” Robinson told Fortune in a video call. “I got to UCL, and I was super ambitious. I wanted to read all the books in the first week; I wanted to get ahead. And I got there, and I just thought the people here—the teachers and the students—they just aren’t that ambitious, they don’t really want to do the things I want to do.”

Many of his classmates, he said, just wanted to “work for a couple hours a day and go to a party.”

“It’s just not in my nature to do that,” he added. “I don’t drink. I don’t go to parties. I just like working. And business was the only platform that gave me the opportunity to work as hard as I wanted for as long as I wanted.”

Robinson dropped out of college just two weeks after enrolling in his courses—and he soon found success with his first company.

As the pandemic took hold, and sales of hand sanitizers skyrocketed around the globe, Robinson had a stroke of inspiration. He came up with a design for small cards which, when snapped, dispense a single dose of hand sanitizer—an idea that led to the founding of startup Gelcard.

According to Robinson, however, there was “no light-bulb moment”—he simply borrowed from existing ideas.

“Such technology has existed for a while in other industries, with things like honey and sunscreen already packaged like this,” he explained. “When I was 19, locked down at home, I was playing around with one and, with hand sanitizer shortages all over the news, simply wondered if you could put hand sanitizer inside.”

After dropping out of college, Robinson spent the remainder of his student loan on Gelcard’s first stock order, tracking down “the very finest ingredients possible” and using suppliers in Italy to create a product with more—and higher quality—ingredients than those in most sanitizers already on the market.

The investment paid off.

“Since day one we’ve been profitable,” Robinson told Fortune.

Avoiding a lifestyle inflation trap

In the first two years of being a founder, Robinson made $250,000 in profit, according to documents seen by Fortune. The company was raking in six-figure sums within the first six months of operations—but Robinson has never been tempted to use any of the cash to fund a lifestyle of excess.

“Because I’m still 22, most of my friends are now graduating with a lot of student debt, and because of the sort of person I am I don’t feel like I have to fall into a lifestyle inflation trap: When you earn a bit more, you spend more, so you don’t actually have any more money,” he explained. “I’m quite comfortable with the prospect of being relatively cash poor for my twenties, with the prospect that [down the line] if I exit Water2 [another Robinson brand] or Gelcard or whatever it might be, I could become very, very wealthy very, very quickly.”

He added that being an entrepreneur was financially risky, but he was comfortable pursuing that risk.

“If financial security is what you’re counting on, I wouldn’t recommend running a company,” he said. “I have the ability to get wealthy, but I also have the ability to get very poor. So there’s a risk, but money is certainly not the reason I do what I do.”

Old-fashioned networking

To date, Gelcard has worked with a slew of high-profile businesses including Google, McKinsey, and Marriott Hotels.

“No one had seen hand sanitizer in that type of mechanism before,” Robinson said when asked about how he differentiated his product from all of the competitors suddenly flooding the market in 2020. “Many companies pivoted to PPE-type products—face masks, hand sanitizer—but there was no real innovation, they were just selling big quantities of hand sanitizer.”

Robinson also took a tried-and-tested approach to selling his product, but gave it a unique spin to land his first big contracts, drawing on his network but reaching out in a way that’s almost unheard of in the modern business world.

“I knew nothing about business, so I wasn’t doing the conventional things like allocating ad spend to the word face mask, because I didn’t even know that was a thing,” Robinson recalls. “I was handwriting letters to people—and I was probably the only person doing it. And that was effective. So the product was unique, but also I think my approach was unique.”

The 22-year-old founder reached out to fellow alumni from his high school who graduated decades before himself and who had since started or taken the reins of companies that were potential clients for Gelcard.

He would spend hours researching their backgrounds, mentioning personal details—such as which university they went to or old articles in which they were mentioned—in his letters. For one recipient, Robinson had found a copy of his school photo from the 1950s, and noted in the letter that he had been the tallest in his class.

“I had no plan, but I had a belief in the product and more than that, belief in myself,” Robinson said. “I just thought, ‘It’s very unusual for anyone to write a handwritten letter to a CEO—and it’s really unusual for a 19-year-old to do it.’”

Eventually, one of his letters resulted in Gelcard landing its first big customer—the Wolseley Hospitality Group, which owns 15 high-profile restaurants in London.

“I spoke with [that contact] quite recently over coffee, and he said if I hadn’t written the letter in that way, it would never have got his attention,” Robinson said. “Reaching profitability was only made possible because our first-ever client was this [major] hotel group that placed a big order upfront.”

His next big idea: Water filters

In the background, he was also quietly working on another company, Water2, which sells water filters and canned filtered water. The company, which was officially launched earlier this year, claims its filters—attached directly to the kitchen tap—are 1,333 times more effective than filter jugs, and can remove almost all bacteria, microplastics, and chemicals like chlorine from drinking water.

He reinvested “basically all” of the profit from Gelcard into Water2, which works closely with UCL—the university Robinson dropped out of at 19.

“By 2030, I want Water2 to be one of the most consumed drink brands in the world—up there with Coca-Cola, top-selling beers, Pepsi, tea,” he told Fortune.

The first step to achieving that goal? Seeking out investors—for the first time ever.

“Pretty much every [dollar] I’ve ever made I’ve just reinvested back into the companies instead of pocketing the cash,” Robinson said. “But later this year, we’re looking to raise funds for the first time to take Water2 to a new global market.”