According to scientists I spoke with, the quality of your slumber has more repercussions on your happiness, intelligence, and health than what you eat, where you live, or how much money you make. Not to be a downer, but chronic sleep deprivation, which Amnesty International designates a form of torture, has been linked to diabetes, cancer, high blood pressure, heart disease, stroke, learning difficulties, colds, gastrointestinal problems, depression, execution (the sleep-starved defense minister of North Korea is rumored to have been shot after dozing in the presence of Kim Jong-un), world disasters (the Challenger explosion, the Three Mile Island meltdown), and non-disasters ... Many scientists have come to believe that while we sleep the space between our neurons expands, allowing a cranial sewage network—the glymphatic system—to flush the brain of waste products that might otherwise not only prevent memory formation but muck up our mental machinery and perhaps eventually lead to Alzheimer’s. Failing to get enough sleep is like throwing a party and then firing the cleanup crew. ... A National Institutes of Health study showed that twenty-five to thirty per cent of American adults have periodic episodes of sleeplessness and twenty per cent suffer from chronic insomnia. On the advice of sleep doctors, fatigue-management specialists, and know-it-alls on wellness blogs, these tossers and turners drink cherry juice, eat Atlantic perch, set the bedroom thermostat between sixty-seven and seventy degrees, put magnets under the pillow, curl their toes, uncurl their toes, and kick their partners out of bed, usually to little avail. ... The ancient Romans smeared mouse fat onto the soles of their feet, and the Lunesta of the Dark Ages was a smoothie made from the gall of castrated boars.