““Keystone habits say that success doesn’t depend on getting every single thing right, but instead relies on identifying a few key priorities and fashioning them into powerful levers.” For me, the most powerful keystone habit has been sleep. Once I changed the amount of sleep I was getting, and started regularly getting seven to eight hours of sleep a night, other habits, such as meditation and exercise, became easier. Willpower alone is not enough. As a number of psychological studies have shown, willpower is a resource that gets depleted the more it’s used.””