Life is a series of progressions, from the minor second to second changes to major life decisions; "phases," rituals, shifts of world view. Many people of all ages look back on earlier periods with a sense of nostalgia. Topic: Is dwelling on the past useless or a healthy part of growth? i.e. Remembering our past can help us learn, but if we view it negatively (because we miss it, for example), does that hold us back? Is there a significant difference between regret and nostalgia?