Bryan Johnson reveals sleep is the most important thing for slowing down aging “When you don’t sleep well your prefrontal cortex goes offline and your willpower plummets. So the next morning when you can either eat the croissant or the bowl of berries, you’re going to eat the croissant even though you don’t want to and you know how it will make you feel. Lack of sleep causes your willpower to plummet” “When you engage in those bad habits you lose even more willpower. So when people feel out of control, it’s because they have no willpower reserve left. They’ve spent all of it and they’re just an animal”