" Focus is one of the main pillars of self-discipline; a person who lacks the ability to focus is almost certainly one who will also lack discipline. Focus itself is dependent on something that neuroscientists call executive functions. The three executive functions that we are most concerned with when it comes to being disciplined are working memory, impulse control, and cognitive flexibility and adaptability. You can see why they are aptly named the executive functions. Your brain has to be able to set and pursue goals, prioritize activities, filter distractions, and control unhelpful inhibitions. "

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