Kundera's 1984 novel follows two couples in Prague before and after the Soviet invasion of 1968, but its real subject is the philosophical question announced in the title: is life's lack of rehearsal, its uniqueness, a burden or a liberation? The novel moves between story and essay, between characters and ideas, in a way that recalls Dostoevsky while remaining distinctively Kundera's own. Kitsch, weight, lightness: these become vocabularies for understanding existence. The novel made Kundera internationally famous and remains his most widely read work.