Zuckerberg is really saying two things: First, this is a change that is as big as they get. “I just think that this is the future,” he said. “People want to share in ways that don’t stick around permanently, and I want to make sure that we fully embrace this.” Second, Zuckerberg is summoning the resilience of his company. That is to say: Remember the last time investors worried about Facebook making it through a huge product transition, and then its share price went from an average of $35 in 2013 to $176 over the next five years?

But Zuckerberg’s admissions throughout the investors call are remarkable. More or less, he said the company has been wrong on several of its core product ideas over the past few years, and that now it is adopting its competitors’ postures.

You could have sworn Snapchat CEO Evan Spiegel was speaking through Facebook’s CEO on the call when Zuckerberg began talking about messaging. “Public sharing will always be very important, but people increasingly want to share privately too, and that includes both just smaller audiences with messaging and ephemerally with Stories,” Zuckerberg said. “People feel more comfortable being themselves when they know their content will only be seen by a smaller group and when their content won’t stick around forever. Messaging and Stories make up the vast majority of growth in the sharing that we’re seeing.”

This is a pretty wild admission from Zuckerberg. The very thing he built Facebook around—a public record of your life—is not the social norm he thought it would be. Messaging apps that recaptured “sharing” as a private, ephemeral phenomenon and not Facebook’s public, permanent practice were one of the key threats to Facebook that experts identified to The Atlantic as far back as 2014. Facebook now has three major messaging platforms, counting Instagram as well as WhatsApp and Messenger. And it is clear that this notion of sharing has eroded the power of News Feed. In its own way, this is a victory for privacy advocates.

Then there was the discussion of video. In 2014, Zuckerberg said News Feed would be “mostly video” in five years. Video, after all, drove up engagement metrics. But, he admitted Tuesday, people didn’t like it. “For a few years, we saw a trend where people’s time was increasing primarily because they were consuming more video and public content, even as they interacted with friends and family less,” Zuckerberg said. “But people were telling us what they wanted was to interact with people more. So we didn’t think that this trend was sustainable.”

Read: How Facebook’s chaotic push into video cost hundreds of journalists their jobs

The company reversed course and “purposefully reduced time spent on things like lower-quality viral videos and news.”

All these admissions and reversals and refinements reopen a crucial question about Facebook: Is the platform the social-media wave driving user behavior, or is it, as Andreessen Horowitz’s Ben Evans puts it, “extremely good at surfing user behavior”?