Tereza carries a “large and enormously heavy” suitcase throughout much of The Unbearable Lightness of Being, and it symbolizes Tereza’s figuratively “heavy” character formed by her devotion to love and deep emotional connections. But Tereza’s suitcase also represents the inevitable weight of human existence within Kundera’s novel. When Tereza first arrives in Prague, she lugs the massive bag along with her. It holds her entire life, which she plans to “offer up” to Tomas, a perpetual bachelor and serial womanizer. Tomas’s character is “light”—he is sexually liberated and unattached—compared to Tereza and her huge suitcase, which serves as the physical representation of her emotional baggage, so to speak. Even though she tries in different ways, Tereza never manages to rid herself of her heavy bag. When she leaves Tomas in Zurich and heads back to Prague, the suitcase goes along with her, suggesting that Tereza’s “heaviness” is a key part of her core identity.
Kundera’s novel explores the philosophical theory of eternal return and Friedrich Nietzsche’s idea of cyclical existence as “the heaviest of burdens.” According to Nietzsche’s understanding of eternal return, within a cyclical existence, “the weight of unbearable responsibility lies heavy on every move we make.” Conversely, a life which does not return “is like a shadow, without weight.” Kundera ultimately rejects the notion of eternal return and posits that since human life only occurs once, one’s existence is incredibly light. Despite the supposed weightlessness of human existence, however, Kundera’s characters are not able to fully rid themselves of all heaviness, and Tereza’s suitcase is evidence of this. Thus, Tereza’s heavy suitcase represents the inescapable weight of human existence in the face of “the unbearable lightness of being.”