The process of becoming happy is dependent on times of challenge. This is so that the decision to become at-peace and from there, to become happy, will allow you to gain in strength. Thus you can gain enjoyment from the process of knowing that you have effected this change in your circumstance. Challenges introduce contrast to your life. Contrasts bring meaning to your experiences. For example, times of happiness are richer by contrast, because of other times you experience when you are not happy - "too many peaks can make a plain..."