The Unbearable Lightness of Being - Milan Kundera

The Unbearable Lightness of Being (1984), by Milan Kundera, is a philosophic novel about a man and his two women and their lives in the Prague Spring of the Czechoslovak Communist period in 1968. Although written in 1982, the novel was not published until two years later, in France; the Czech: Nesnesitelná lehkost bytí and French: l'Insoutenable légèreté de l'être titles are the more common worldwide.
The Unbearable Lightness of Being catalogues Prague in 1968, the artistic and intellectual life of Czech society during the Communist period, from the Prague Spring to the USSR’s August 1968 invasion and its aftermath, and until 1984. The characters are Tomáš, a successful surgeon; his wife Tereza, a photographer anguished by his infidelities; Sabina, a free-spirit artist, who is Tomáš’s lover; and the secondary characters Franz, the Swiss university professor lover of Sabina; and Simon, Tomáš’s estranged son from an earlier marriage.
Challenging Friedrich Nietzsche’s concept of eternal recurrence (the universe and its events have already occurred and will recur ad infinitum), the story’s thematic meditations posit the alternative that each person has only one life to live, and that which occurs in that life, occurs only once shall never occur again — thus the “lightness” of being; whereas eternal recurrence is the “heaviness” threatening the meaning of said life.
The German expression Einmal ist keinmal encapsulates “lightness” so: “what happens but once, might as well not have happened at all. If we have only one life to live, we might as well not have lived at all”; if concluded logically, life ultimately is insignificant. Hence, because decisions do not matter, they are rendered light, because they do not cause personal suffering. Yet, simultaneously, the insignificance of decisions — our being — causes us great suffering, perceived as the unbearable lightness of being consequent to one’s awareness of life occurring once and never again; thus no one person’s actions are universally significant. Said insignificance is existentially unbearable, given that people want their lives to have transcendent meaning. As literary art, The Unbearable Lightness of Being is considered a modernist humanist novel and a post-modern novel of high narrative craft.