LitCharts assigns a color and icon to each theme in The Unbearable Lightness of Being, which you can use to track the themes throughout the work.
Time, Happiness, and Eternal Return
Lightness, Weight, and Dichotomies
Sex, Love, and Duality of Body and Soul
Words and Language
Power, Politics, and Inequality
Summary
Analysis
The request to enter Cambodia is yelled for the third time through the megaphone, but it is again met with silence. Franz feels a sinking depression that quickly turns to anger. Why did he even bother coming here? Franz has the urge to run into Cambodia anyway, sacrificing himself for the cause, “putting his own life on the scales.” He desperately wants to prove that the Grand March “weighs more than shit,” but instead, he walks back to the bus.
The Grand March is meaningless, therefore it is light according to Kundera’s understanding of lightness and weight. Franz wants to cross into Cambodia and put “his own life on the scales”—that is, add weight and meaning to the cause—but Franz’s life is meaningless as well and also has no weight, so he goes back to the bus, defeated.