For many young entrepreneurs, a $1 billion exit would be a crowning achievement--and potentially the beginning of a long and very cushy retirement. Not for Instagram co-founder Kevin Systrom. He still comes in to work everyday determined to build a better photo-sharing app.

"No one looks at this as a cashing out or an end," Systrom said Thursday night in his first public interview since the acquisition. "A lot of people ask questions that relate it to an end and for me it’s really puzzling because I show up to work everyday trying to figure out how we can leverage Facebook to be 10 times as big... It comes down to the mission we’ve had since the beginning: Everyone in the world should be using this to share what’s happening."

Instagram joined Facebook as a separate entity in early September when the acquisition officially closed. Systrom insisted that the big payday hasn't changed his vision for the company. 

“The second anyone starts thinking ‘Oh, we’ve won,’ you start acting differently,” Systrom told the audience during the interview with PandoDaily. “That’s one of the things in Silicon Valley that companies need to work actively against. If I don’t act any differently, then I don’t think we’ve won. Selling for a certain amount of money is awesome, but it’s not what gets me up in the morning. The goal should be about creating value.”

Systrom said even from the beginning he was passionate about building a product with value--maybe even a little too passionate about it.

"When people are starting a start-up, they’re actually starting a product--not a start-up," he said. "People don’t realize that eventually you have to start the start-up--the hiring, the financing, and the firing in some cases, the people stuff... that’s one of the biggest lessons I’ve learned and I would focus on that stuff way earlier and that’s probably why we were six people for so long. We all loved building product so much and we didn’t love building an organization."

Now that Systrom and Instagram are part of a much bigger organization with many more resources at his disposal, he says he can focus on a much bigger goal: using the product to change the world.

But can a photo-sharing app really change the world?

Systrom said he believes Instagram is on pace to do so--after all, images have no language barrier, he explained. Plus, while not everyone will have a computer in the future, everyone will have a phone--and that could be very powerful for Instagram.

"What can you do when a camera has a network? You can share images instantly to anyone in the world, you can cover events instantly, you can discover places instantly," he said. "What we did was build a product around that shift.”