Mark Zuckerberg's zeal for personal betterment has made him something of a guru to self-help aficionados, lifehackers, and strivers of all stripes. One co-founder of a startup with a multibillion-dollar valuation told me he's so inspired by the Facebook CEO and his annual personal challenges, he listens to the soundtrack of The Social Network to psych himself up for board meetings and presentations. (Never mind that the film is not exactly a hagiography.)

For the most part, though, the labors Zuckerberg assigns himself aren't the Herculean type. The first one, in 2009, was to wear a necktie every day. In 2011, he made a pact with himself to eat meat only from animals he killed with his own hands. In 2015, he promised to read a book every two weeks. Even the more impressive challenges, like learning to speak passable Mandarin or coding a rudimentary A.I. system to operate devices in his home, are the sort a smart person can expect to accomplish in a year if he sets aside enough time. 

Zuckerberg's task for 2018 is something very different. In a post on his page, he announced his intention to forego challenges of the self-improvement variety and to instead focus on "fixing" the "important issues" facing his company. "The world feels anxious and divided, and Facebook has a lot of work to do -- whether it's protecting our community from abuse and hate, defending against interference by nation states, or making sure that time spent on Facebook is time well spent," he wrote.

Just how he'll go about tackling those problems wasn't spelled out precisely, with Zuckerberg suggesting he'll be "bringing groups of experts together to discuss and help work through" questions like whether the internet is becoming too centralized and whether the technology behind cryptocurrency could improve social media. 

It's not just the largeness or vagueness of the goal that sets this year's challenge apart. It's also the first time Zuckerberg has publicly committed to something he appears likely to fail at.

For Zuckerberg to make meaningful progress toward all of the objectives he outlined would require him to reexamine and reject assumptions central to the success he has attained so far. Even if he could do that, there's little in his history to suggest he will. 

Take the goal of "making sure time spent on Facebook is time well spent." The phrase "time well spent" is a nod to the work of Tristan Harris, a former "design ethicist" at Google who campaigns against technologies that encourage addictive and mindless behaviors in users. 

Harris is an outspoken critic of using engagement--as measured by screen time, click-throughs, likes, and other actions--as a metric of success. Rather, he thinks product-makers should measure value in "net positive contributions to people's lives." But at Facebook, engagement is and has always been the primary success metric. For the company to move away from it onto some new standard would be a tectonic shift affecting every part of the business, from product design to ad sales.

It's inconceivable an enterprise that booked $10.3 billion in revenue in its most recent fiscal quarter, almost all of it from advertising, would simply abandon the thinking that got it to this point. But without moving decisively away from engagement as the ur-goal, any talk about "time well spent" is just that--talk. 

Likewise, there's good reason to think the goal of "protecting our community from abuse and hatred" is a non-starter as long as "our community" means a user base of more than two billion people. Internet entrepreneur Cody Brown makes a compelling case that the inability of Facebook (and Twitter, YouTube, Reddit, etc.) to enact consistent and enforceable policies around things like fake news and inflammatory speech arises from their foundational decision to treat users all over the world as a single audience.

"If you create a platform that is meant for everyone in the world you will evade the responsibility to say what is or is not true in the world," he writes. "So how do we restore trust on the web at a global scale? How do we rebuild a common, civic, universe of information online? Maybe the most helpful answer to accept on a product level is that we'll never be able to do it at global scale and we need to stop trying before it's too late."

Again, Zuckerberg has gestured to this idea, adopting "meaningful groups" as another of his new totem-phrases, and suggesting that the solution lies in Facebook's hosting a constellation of smaller overlapping social networks, each of which can set its own standards. People who value free speech above all can gather in one corner, while those who want to avoid hate speech or triggering language can associate somewhere else.

There's nothing wrong with this idea, but there's an obvious tension between it and Facebook's other imperatives, from the high-flown mission of connecting the world to the grubby business of maximizing the eyeballs on viral pieces of content. Unless Zuckerberg is prepared to commit to "meaningful groups" as the default mode of experience on Facebook--versus the decidedly meaningless and unmodulated but oh-so-addictive free-for-all of the News Feed--the difference in the experience of the average user 12 months from now is likely to be negligible. 

Underestimating the determination and ingenuity of Mark Zuckerberg has never been a wise move. There's no shortage of investors and competitors who can attest to that. But it's all too possible that everything he has accomplished to date has delivered Zuckerberg to a place where he simply has too much at stake to accept the painful tradeoffs required to solve what he has correctly identified as Facebook's most pressing problems in 2018.

If that's the case, Zuckerberg will have to learn yet another new skill: how to fail.