p>Nostalgia is “a sentimental longing or wistful affection for the past” (Pearsall, 1998, p. 1266). This dictionary definition aligns well with lay conceptions (i.e., prototype analysis; cf. Rosch, 1978). Laypeople (Hepper, Ritchie, Sedikides, & Wildschut, 2012) across 18 cultures (Hepper et al., 2014) think of the construct “nostalgia” as encompassing fond, rose-colored, and personally important (i.e., self-defining) memories of one’s childhood or relationships, but also as encompassing pining and wishing for momentary returns to the past. They think of it, then, as a bittersweet (albeit more positive than negative) emotion that is relevant to the self and close others. Both content analyses of nostalgic narratives (Abeyta, Routledge, Roylance, Wildschut, & Sedikides, 2015; Holak & Havlena, 1998; Wildschut, Sedikides, Arndt, & Routledge, 2006, Studies 1-2) and in vivo manipulations of nostalgia (Baldwin, Biernat, & Landau, 2015; Wildschut et al., 2006, Studies 5-7; Stephan, Sedikides, & Wildschut, 2012) have corroborated these properties of the emotion.</p