The whole world is exhausted. And it’s killing us.

But particularly me. As I write this, I’m at TED 2019 in Vancouver, which is a weeklong marathon of talks and workshops and coffee meetings and experiences and demos and late-night trivia contests and networking, networking, networking. Meanwhile, I’m sick as a dog with a virus I caught from my 3-year-old, I’m on deadline for what feels like a bazillion stories, and I’m pregnant, which means I need coffee but can’t have too much, and need sleep but can only lay on my left side, and can’t breathe without sitting propped up with a pillow anyway, since I can’t safely take any cold medication.

According to neuroscientist Matthew Walker, I’m doing serious damage to my health—and life—by not sleeping enough.

“The decimation of sleep throughout industrialized nations is having a catastrophic impact on our health, our wellness, even the safety and education of our children. It’s a silent sleep loss epidemic. It’s fast becoming one of the greatest challenges we face in the 21st century,” Walker, an expert in sleep at UC Berkeley and author of the best-selling book Why We Sleep, told a rapt TED audience on Thursday.

After a morning of bleak talks on climate change and the harm of viral misinformation online—punctuated by frequent exclamations of “Well, that was alarming” by TED science curator David Biello, and stolen glances at Twitter for updates on the Mueller report and the happenings in the outside world—Walker’s talk felt like a jolt of caffeine to a weary system. (A comparison Walker might hate. He warns, in the strongest possible terms, about the harms of that particular stimulant.)

He ran down all the ways in which sleep deprivation hurts people: it makes you dumber, more forgetful, unable to learn new things, more vulnerable to dementia, more likely to die of a heart attack, less able to fend off sickness with a strong immune system, more likely to get cancer, and it makes your body literally hurt more. Lack of sleep distorts your genes, and increases your risk of death generally, he said. It disrupts the creation of sex hormones like estrogen and testosterone, and leads to premature aging. Apparently, men who only sleep five hours a night have markedly smaller testicles than men who sleep more than seven.

“Sleep loss will leak down into every nook and cranny of your physiology,” he said. “Sleep, unfortunately, is not an optional lifestyle luxury. Sleep is a nonnegotiable biological necessity. It is your life support system.”

Of all the TED Talks I’ve heard this week, this one felt aimed right at me. At my heart. And my withered and overworked hippocampus, my brain’s “information inbox,” as Walker calls it. At my swollen, dark-ringed eyes. Yes, OK, maybe it’s because I’m so tired, and was so primed to hear it. But I wasn’t alone.

Everyone is obsessed with sleep. And they know they’re not getting enough—hence the growing demand for sleeping pills, the emergence of sleep tracking devices (Walker wears an Oura Ring to track his), smart beds, Alexa integrations to put you to sleep, and mindfulness sleep apps. Arianna Huffington famously left journalism to found a company devoted to sleep and wellness.

After Walker’s talk, he was mobbed by acolytes in the conference center desperate to tell him how much his book—which covers the same topic as his TED talk—changed their lives, how they’d given up caffeine and alcohol and stopped feeling bad for leaving parties early to get sleep or refusing to look at work emails in bed. As the next session of TED talks was starting up, Walker kept trying to escape so he could watch, but people wouldn't let him pass. They wanted to know what to eat, when to sleep, how to dream.