He wasn’t the awkward or sweaty stereotype we’ve come to know over the years. He was sure of himself. And he was selling–hard.

Whether he’ll admit it, going public has changed Mark Zuckerberg. Sure, he declared “our mission was not to become a public company,” on the day of Facebook’s IPO. Sure he wrote “Facebook was not originally created to be a company,” in the shareholder letter of the company’s S-1.

But at this point, all of that is just posturing, because he has shareholders, many of which have lost millions of dollars on his company. And he has employees, plenty of which have watched their net worth drop by millions. He himself has lost billions with the freefalling shares of Facebook.

Today on stage at TechCrunch Disrupt, he called the stock’s performance “disappointing.” He admitted it is not good for morale. But the most important takeaway from that portion of the interview was unspoken. After all that posturing about only caring about the mission, the reluctance to participate in the IPO road show, and launching a $1 billion acquisition of Instagram during a quiet period–consequences be damned–today a humbled Zuckerberg showed that he recognizes he has to play the game.

His goal since early days was to follow the IPO playbook of Google. But it turns out following in the footsteps of Google is harder than it looks. It’s not just about delaying an IPO and building pent-up demand. The aftermarket performance simply hasn’t given him the luxury of being the new Larry and Sergey.

Facebook’s entire history has been about selling shares in a vision that was always a year or two away from reality. The first time that strategy failed was when it tried to go public–it hit a wall. And like a cock-sure bird flying into a plate glass window, since then it’s been sliding down that wall, painfully. For Facebook to get through something it had never experienced before, Zuckerberg had to change. Anyone who has watched him build Facebook has marveled as his almost robotic ability to learn and master new skills when the company’s challenges demand it.

Toiling away on product as the boy genius behind the scenes works great when the results happen to be fantastic. When they aren’t, he needs to step up and do the job most CEO’s are charged with: Cheerlead the shit out of your stock.

Which is what he did today. In his first Q&A since the IPO in March, Zuckerberg made some uncharacteristic comments, hitting phrases investors like to hear such as “building value” and “we care about our shareholders.”

“There’s no doubt that we’re a mission-driven business… but you can’t just focus on that,” he said. In a flurry of mile-a-minute speaking, he essentially said that in order to build a great service, he needs to build a business, and in order to do that, he needs to build a platform, and in order to do that, he needs to build a great team. And that takes money. “The best people want to work on a mission they believe in, and make money,” he said. “We need a business model too.”

“Building a mission and building a business go hand-in-hand,” he said. “Building a good business is important to employees, advertisers and developers. We have a healthy understanding that we need to do both.”

The capitalist bit worked: Facebook valuation increased by more than $1 billion in afterhours trading, all over a little 30 minute interview. You can see why his handlers pushed him to get out there and say something. The silent treatment clearly wasn’t working.

He brought back the “mission-driven” rhetoric in the end: Arrington asked, “Are you still having fun?”

“For me it’s not really about fun, it’s about the mission,” he said. Sure. That, and shareholder value.

Today was a success for Mark Zuckerberg, public company CEO. The reality is, it’s one of the first he has had since March. But the big win for investors may be that Mark Zuckerberg the public company CEO has finally shown up.

[Image via Adweek]