In "The Swan Thieves," Elizabeth Kostova explores the complexities of human relationships and the inherent differences between individuals. The quote "Strangers are strange to each other" highlights the idea that encountering someone unfamiliar can evoke feelings of confusion and curiosity. It reflects the notion that each person brings their unique experiences, perspectives, and emotions, making interactions with strangers often unpredictable and intriguing.

This theme invites readers to consider how we perceive and relate to those we do not know. Kostova suggests that while we may share common ground, the nuances of each person's life can lead to misunderstandings or unexpected connections. Ultimately, the exploration of these interactions deepens our understanding of humanity and the intricate web of relationships we navigate.