" But sometimes trying to be disciplined is overwhelmingly difficult. It can make you want to break down or tear your hair out at the brink of frustration or exhaustion. Luckily, there is a set of questions you can ask yourself to get back on track. The questions are intended to return your focus to your goals and pursuits—the things that motivate you to be disciplined in the first place. They might also shed light on your real reasons for wanting to persist or quit, which can be illuminating. "

― Peter Hollins , The Science of Self-Discipline: The Willpower, Mental Toughness, and Self-Control to Resist Temptation and Achieve Your Goals