The term ‘nostalgia’ was coined by a Swiss doctor in the 17th century to describe the homesickness experienced by mercenaries fighting far from home (from the Greek ‘nostos’ – the desire to return home – and ‘algos’, meaning pain). That’s not so different from how we use the term to refer to thinking fondly or wistfully of the past, such as places you’ve been or people you’ve known. In fact, psychologists have shown that nostalgia of this kind has various psychological benefits, such as countering feelings of loneliness or existential anxiety. But a yearning for a past that you never actually experienced is different (and has its own name, ‘anemoia’, according to the Dictionary of Obscure Sorrows).