In "The Unbearable Lightness of Being" by Milan Kundera, the character experiences a troubling transformation as she begins to feel jealousy towards her partner. Initially, this jealousy may seem like a natural emotional reaction, but it soon becomes a source of discomfort and conflict. Rather than viewing her jealousy as a testament to their love, Tomas perceives it as a heavy burden, complicating their relationship dynamics.

This shift in perception illustrates the complexities of love and the emotional challenges that arise when both partners grapple with their feelings. Tomas believes that the weight of jealousy ultimately detracts from the lightness and freedom that love should ideally embody, foreshadowing the struggles they will face together.