In our always-on society, there’s great temptation, and even pressure, to shortchange sleep. In fact, there's a real misconception that sleep deprivation is some kind of heroic feat, a boastworthy indication of how hard you work, how early you can wake up, how little sleep you (think) you need, how active and social and busy you are. But sleep isn't just a cozy reward after a long day—and it's certainly not a sign of laziness or weakness.