We all know what it's like to wake up in the middle of the night and wonder what time it is and is everything ok.
But once you check your phone, you're wide awake.
Mark Zuckerberg's wife was waking up, wondering if it's time for the kids to be waking up... and stressing out about it.
So he built her this sleep box, which lets her know (through a soft light) when it's between 6am and 7am.... otherwise, it's dark, so she knows to roll over and go back to sleep.
Now we all want a sleep box. And a husband like Mark.