Agnes Arnold-Forster was once a very nostalgic child. An avid reader of Enid Blyton novels, she tells us, she unsuccessfully begged her parents to “divert me from my 1990s London primary to a boarding school in 1950s Cornwall”. Although her training as an academic historian naturally taught her to be suspicious of such yearnings for an imaginary past, she has now written a book that combines wide-ranging historical analysis with a (cautious) “defence of nostalgia”. While neuroscientists sometimes treat emotions as human universals, historians are keen to show how the words we use to describe our feelings, and indeed the...