Nostalgia

Nostalgia is an emotion usually described as a bittersweet longing for the past, most often for a period remembered through happy memories, a kind of sad pleasure bound up with longing for something, real or romanticized, that can never actually be recovered, and it can also shade into a kind of homesickness. The word is a coined compound of the Greek words for homecoming and pain, first used by a seventeenth-century medical student to describe the anxieties he observed in Swiss mercenaries fighting far from home, and for much of the early modern period it was treated as a medical condition, a form of melancholy, before becoming a major theme of the Romantic movement. People show a documented tendency, tied to cognitive biases such as rosy retrospection, to remember the past more fondly than it likely was while viewing the future more darkly, and when that same tendency is applied to a whole society or institution rather than to a person's own life, it is given the separate name declinism. The scientific literature on nostalgia mostly studies it as a response to a person's own life, and researchers have found that emotional memories of this kind are processed first through the amygdala, with music, film, television, video games, weather and familiar surroundings all documented as strong triggers of the feeling.