Meet John Collison, the 27-year-old Harvard dropout whose tech startup turned him into the youngest self-made billionaire in the world

John was born in Limerick, Ireland, in 1990, and his family eventually settled in the small village of Dromineer.

Collison was a brilliant student, and he finished with the highest possible marks on his Leaving Certificate, the equivalent of final exams in the US.

Source: Independent

Collison was accepted into Harvard before even taking his final exams, which he aced anyway.

Source: Independent

Before he entered college, Collison had already become a millionaire with his older brother Patrick. They had launched a software firm that made it easier for sellers to manage transactions on eBay.

Source: Business Insider

Collison came to the United States to study physics at Harvard in 2009. "It is a weird thing — people are almost surprised that I'm going to college," he told Ireland's Independent at the time. "There's absolutely no doubt that college is what I want to do."

Source: Independent

However, by the next year Collison changed his tune, dropping out of Harvard and heading to Silicon Valley with Patrick to start what would become Stripe.

Source: Bloomberg

At first, the brothers rode their bikes to their Palo Alto office every day, in part because they were too cheap to buy a car.

Source: Bloomberg

Stripe officially made its public debut in 2011. The company simplified the way businesses accept online transactions by allowing them to integrate payment processing into their websites, instead of forcing users to register and make an account every time.

By 2015, Stripe was valued at $5 billion, and in November 2016, it spiked to a whopping $9.2 billion. The valuation brought Collison's fortune to $1.1 billion, making him the youngest self-made billionaire in the world at age 26.

Source: Forbes

Today, the company employs 750 people and is run out of San Francisco. Its customers include huge companies like Lyft and Facebook.

Source: Bloomberg

Collison is a licensed pilot and enjoys flying in his free time.

Source: Business Insider

He's also an avid hiker and runner, often participating in company excursions and fun runs with his coworkers.

Source: Business Insider

He posts pictures on social media of his adventures with fellow Stripe employees, like this trip up Mt. Tamalpais in the Bay Area.

Source: Business Insider

Stripe board member Mike Moritz told Bloomberg that the Collisons were more "humble and well-rounded" than your average tech moguls. "There's such an improbability to their story — that these brothers from a little village would come to build what could well be one of the most important companies on the internet."

Source: Bloomberg