The process of building a habit can be divided into four simple steps: cue, craving, response, and reward [...] If a behavior is insufficient in any of the four stages, it will not become a habit. Eliminate the cue and your habit will never start. Reduce the craving and you won’t experience enough motivation to act. Make the behavior difficult and you won’t be able to do it. And if the reward fails to satisfy your desire, then you’ll have no reason to do it again in the future. Without the first three steps, a behavior will not occur. Without all four, a behavior will not be repeated.