Have you by any chance noticed yourself feeling less friendly toward Facebook lately? Perhaps you still open the app a few times a day to check your notifications and scroll through a few posts, comment on a viral video, "like" a story from The New York Times. But when it comes to the personal stuff--your vacation photos, your job announcements, your gripes about the wait at the DMV--you're just not sharing it like you used to.

If so, you're not alone. Far from it. In the past few months, Facebook has quietly shifted into crisis mode. According to The Information, "original broadcast sharing"--i.e., posts consisting of users' own words and images--fell 21 percent from 2014 to 2015, contributing to a 5.5 percent decrease in total sharing. In response, the company created a task force in London whose mission is to devise a strategy to stem the ebb and get people sharing again. Among the measures taken so far: a change in the News Feed algorithm that privileges original status updates over professional content like news links and viral videos, and Wednesday's mishap-marred rollout of a new live-video-streaming feature. 

It's a stunning reversal of fortune for Facebook, whose strategic emphasis for the past few years has been on getting media companies and celebrities to put more of their premium content on Facebook. The better (read: more professional) the quality of what's in your News Feed, the more advertisers would pay to be next to it, went the thinking.

That strategy now looks like a backfire. The more Facebook feels like a big stage, the less inviting it becomes to the sorts of people who aren't comfortable performing in public--which is to say, most of us. You've probably noticed how the "friends" who show up in your News Feed most often aren't the ones whose lives you're most interested in but simply the ones who have a lot to say. According to confidential data obtained by The Information, more than 60 percent of users share no personal content in a given week, while the remaining 39 percent share an average of five posts. 

I used to be one of these annoying Facebook exhibitionists. Then, six months ago, my account got hacked and I spent several painful days recovering it. Since then, my relationship with Facebook has changed in a way that I think may shed some light on the troubling trend facing the company. 

At first, my pullback from posting was reactive. I was angry that it had been so easy for my hacker to eradicate the hundreds' of hours worth of supposedly valuable content I had entrusted to Facebook. I was reluctant to get burned again. 

But there was something else, too. In the first hours after the hack, when it seemed possible my account was gone for good, I was flooded with an unexpected sense of relief and lightness. "Oh well," I thought, "maybe I just won't use Facebook anymore." The thought felt good, and the feeling stayed with me even as I got my account back and tentatively resumed posting. 

Changing my password had logged me out on all my devices. As an experiment, I logged back in on my phone but left my laptops logged out. Over the next couple weeks, I was shocked by the number of times my fingers, with no conscious input from my brain, attempted to navigate me to Facebook.com during some lull in my attention span. It was a stark demonstration of how scrolling through my News Feed had ceased to be an activity and become a reflex, a default, a background state. It was something I did not because it provided pleasure or information but simply because the behavior had been so reinforced that it was permanently grooved into my neural architecture. After enough times finding myself staring at the log-in screen and asking, "What am I doing here?" the impulse began, blessedly, to fade. 

It helped immensely that, while my posts and photos got restored after the hack, the underlying data governing my News Feed preferences apparently did not. All the thousands or millions of clicks I had made that Facebook used as inputs to figure out which posts to show me--it was as if they had never happened. When I opened my News Feed, all I saw was posts from a handful of Pages I had liked at some point and updates from friends I'd added since the hack. In other words, my News Feed is noisy, irrelevant garbage--the same thing it always was, but much more noticeably now. I could spend a few hours re-optimizing it for my interests, or I could take those hours plus the 40 or so minutes per day I had been frittering away scrolling my feed and thinking of clever things to say and do something more productive.

Easy call.

Time. That's what all this boils down to. Ultimately, Facebook doesn't care what kind of content gets shared or who's sharing it, as long as it's able to capture an ever-larger share of its users' attention minutes. The problem is, with each experiment aimed at promoting different types of content--New York Times articles one month, Ice Bucket Challenge videos the month after that, livestreamed videos now--it becomes ever clearer to the content makers how little Facebook cares about what any of them do. Just as ordinary users once got the unpleasant sense that Facebook was becoming a venue for professionally produced corporate content, and businesses felt their hard-won Page followings had been stolen from them, now journalists and news organizations are finding their reach curbed as Facebook tries to restore a sense of intimacy and personalization. If filling your feed up with the Hypnotoad from Futurama turned out to be the best way to monopolize your eyeballs and associated personal data, that's what Facebook would become tomorrow. 

Fortunately for Facebook, it's so ubiquitous and so addictive, none of this has really put a dent in the business yet. Facebook's user base continues to grow, including among Millennials, who spend nearly an hour a day Facebooking, according to ComScore.

An hour doing what, exactly, though? Sooner or later, each Facebook user has occasion to ask this question, as I did. The massive decline in personal sharing is a sign that large numbers of people have started to figure out that the value they get out of Facebook is a lot less than the value they put in. For a service that's increasingly just an arbitrage on the human attention span, that's a dangerous epiphany. Ask yourself: If your time is so valuable to Facebook, shouldn't it be at least as valuable to you?