In "Tennyson's Gift," Jessie is confronted with the unsettling idea that mental illness can be inherited, a notion she finds surprising and perplexing. She had always believed that madness was something experienced solely by characters in Shakespearean plays, influenced by external forces rather than a genetic or familial issue. This illustrates her naivety and lack of understanding of psychological complexities.

This concept challenges Jessie's perceptions and invites readers to reflect on the deeper intricacies of mental health. By juxtaposing the idea of inherited madness with the romanticized view of madness in literature, the author, Lynne Truss, highlights a more realistic and often daunting aspect of human experience that resonates with many.