Our most pressing question for this young Irish billionaire? What is it really like being at the helm of one of the world's most impressive start ups?

Patrick Collison likely needs no introduction.

The media is rife with tales of the Limerick man (29) and his brother John (27) Collison, and the runaway success of their tech venture, Stripe.

The company has now been valued at an eye-watering $9.2 billion. Its ascent to Silicone Valley legendary status has been well documented, but little is known about the personalities of the humble brothers behind it.

Stripe co-founders John and Patrick Collison talk with @emilychangtv about why their company doesn't accept cryptocurrencies https://t.co/G7LP7ZhEth pic.twitter.com/M3l4myNn0o

— Bloomberg Technology (@technology) May 31, 2018

Read More: Irish man John Collison is world's youngest self-made billionaire

Speaking to Guy Raz for NPR's hit podcast How I Built This, the duo told how they turned seven lines of code into an international heavyweight on the tech scene.

The brothers told Raz how they founded and sold their first company before they turned 20 and went on to build Stripe, which uses the aforementioned lines of code to power the payment systems of companies all over the world.

When Raz asked when did they sit back and realize Stripe was a huge success, Patrick said that "there's never really been time for that."

(Ahh, bless that Irish humbleness!)

"There's nothing like a young company to every morning remind you that there's so much left to be done, so much that's not yet working the way it should be," Patrick said on the podcast.

Superb podcast with Patrick Collison of @stripe
Stripe’s extraordinary success isnt just a function of the amazing intellect of Patrick and John Collison but is just as much a function of their humility and inquisitiveness. https://t.co/o0pkcb8OIV

— Paul Bassat (@PaulBassat) May 12, 2018

"I mean, it's really quite visceral. You wake up in the morning, and there are 20 emails in your inbox that are sort of somehow all related to things that you're doing badly or wrongly. There is never a moment when it feels successful," he noted.

The cycling-enthusiast said he often thinks about a famous quote from Greg LeMond, a professional cyclist who won two world championships and three Tours de France: "It never gets easier — you just get faster."

Collison, who said he used to cycle a lot, added:

"There's a lot of sort of painful truth to that where, as you cycle more, as you practice more, as you get fitter, as you get faster, as your form gets better, sure, you start cycling faster, your times get better. But the experience of being on the bike never gets easier. The pain that you feel on the first bike ride, that's the same pain that you're going to feel on your 500th bike ride. You'll just be going much faster on the 500th bike ride."

How John and Patrick Collison made Stripe the cashier of the Internet and a $5B company: https://t.co/BotL1btEtk pic.twitter.com/9rcJjj979R

— Forbes Tech News (@ForbesTech) January 5, 2016

"And it kind of feels like that in a startup, where every day now the problems and challenges and, you know, visceral pain is just as acute as when we were starting out. The problem is just in a different form. It's this kind of relentless process of trying to shift what it is that exists and what we've collectively managed to create so far into what we all set out to create in the first place. And we still have quite a ways to go there."

You can listen to the entire Collison brothers episode of "How I Built This" on NPR here.

Read More: Without immigrants, Silicone Valley fails, says Stripe brother

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