The Power of Habit covers the basics on how habits work (cue, routine, reward) and how to manage, change or create them. The author also bring up the interesting concept of willpower fatigue in which willpower and discipline is described more or less as a muscle. This means that willpower and discipline can be both drained or trained, so you should be aware of and plan how you use this resource. Maybe you should not cram a day full with activities that require a lot of your willpower of discipline… This is very closely related to decision fatigue, which is discussed a bit more in the review of The Happiness Advantage.
Overall, The Power of Habit is a quite interesting book if you disregard the questionable last chapter. This chapter discusses questions the individual’s responsibility of their actions when they are just acting out of habit, and did not resonate well with me at all.