When we live with another person, to protect each other's happiness, we should help one another transform the internal formations that we produce together. By practicing understanding and loving speech, we can help each other a great deal. Happiness is no longer an individual matter. If the other person is not happy, we will not be happy either. To transform the other person's knots will help bring about our own happiness as well.
The root cause of any internal formation is a lack of understanding. To practice mindful observation is to look deeply to be able to see the nature and causes of something. One important benefit of this kind of insight is the untying of our knots.