If you thought day dreaming was time wasted, then think again. “Nostalgia is a bittersweet emotion and it encompasses predominantly positive feelings and a tinge of sadness and longing,” Dr Wing Yee, a senior lecturer in psychology and researcher of nostalgia at the University of Winchester, tells British Vogue. “Nostalgic narratives typically feature personally meaningful and somewhat rosy recollections of our childhood or significant life events like birthday celebrations and weddings.” And it is truly beneficial for us to let our minds wander there: “It helps to boost our mood, self-esteem, self-continuity (the sense of connection between our past and present selves), optimism, and meaning in life.”
Source: https://www.vogue.co.uk/arts-and-lifestyle/article/rewatching-films-period-dramas-mental-health