Kevin Systrom and Mike Krieger have lived every entrepreneur's dream.
They launched Instagram on the app store at midnight on Oct. 6, 2010. On April 9, 2012, Facebook announced it was acquiring the company for a deal valued at $1 billion.
Virtually overnight, Systrom and Krieger became very, very wealthy.
But Systrom, who with Krieger left Facebook in September, says the experience was eye-opening in ways one might not expect.
"I think the biggest lesson ... coming into a fair amount of money pretty quickly, was that money itself is no end. It doesn't make you happy. It doesn't solve health problems. It can help in those things," Systrom told TechCrunch's Josh Constine at the South by Southwest conference in Austin, Texas, on Monday.
"Maybe the first day you wake up and you are like, 'Yeah, this is great.' But that goes away pretty quickly," Systrom said. "I don't really wake up in the morning and look at the bank account." It's a benefit, Constine noted, of having a large account.
The first thing Krieger did after making the deal with Facebook — was to get a burger.
"I distinctly remember — and I don't know if most people do this — but I think I craved comfort. It's a crazy decision we have been like talking about it for a couple of really intense days, and I went home to [now-wife] Kaitlyn and was like, 'Let's go to Nopa and get their burger.' It's my favorite burger in San Francisco. This is the most normal thing I can imagine doing."
Practically, the money from the deal doesn't instantly drop into your bank account, Krieger pointed out. And tactically, he and Systrom were both careful to not make any rash changes to their lives for the first couple of years after they sold Instagram.
"There is no way of processing it. And it probably took years for us to fully process it," Krieger said Monday. "I think it is very easy to upend your whole life but instead it is like, we are still the same people."
A mentor of Systrom's had warned him that money doesn't solve many of the hardships that come from being human.
"No matter where you are on the spectrum, you struggle in different ways," Systrom recalled being told.
"What ends up mattering — and one of my mentors likes to say — is is your struggle meaningful? Do you wake up in the morning everyday struggling on things that feel like they mean something to you, like they are to some end? And most of Instagram wasn't about how much money we made. It was waking up every single morning, working with awesome people, some of our best friends still to this day were Instagram employees because we met them there, we were in the trenches with them, working on something that we believed. And that's honestly the thing that got us up every morning, working hard at Instagram. It wasn't about the money."
See also:
Sam Adams founder: Unless you're a sociopath, being happy is better than being rich
Warren Buffett on wealth inequality: 'A rich family' takes care of its own and the US should too
Like this story? Subscribe to CNBC Make It on YouTube!