“Sleep, those little slices of death — how I loathe them,” wrote Edgar Allen Poe, who was no fan of bedtime. But love it or hate it, sleep is essential, and something like 35% of us don’t get nearly enough. Seven hours should be a minimum to stay healthy and wise. One solution: Take a break from your electronics. Make time in the evening to read a book, take a hot bath, or meditate—just turn off your cellphone first. That tweet can wait until the morning.