It's easy to look back and get caught up in the nostalgia of childhood. Everything just seemed easier back then. However, researcher Alan Hirsch says nostalgia is "a longing for a sanitized impression of the past, what in psychoanalysis is referred to as a screen memory-- not a true recreation of the past, but rather a combination of many different memories, all integrated together, and in the process all negative emotions filtered out."
Hirsch also points out that nostalgia does not relate to a specific memory, but rather an emotional state. Psychologist Erica Hepper says that the usefulness of nostalgia varies with age, with young adults participating in it most. Once we hit middle age and older we tend to have a decline in nostalgic thoughts.