In the context of "The Last Olympian" by Rick Riordan, the quote emphasizes the importance of trust in relationships. The protagonist reflects on the significance of having a trustworthy companion, suggesting that if he cannot rely on this person, it undermines his ability to trust anyone else. This quote underlines a central theme in the narrative, where loyalty and trust are pivotal for overcoming challenges.

This sentiment resonates throughout the book as the characters face formidable adversaries and difficult decisions. The idea that trust is foundational to personal bonds not only drives the plot but also shapes character development. It illustrates the vulnerability and strength that come from trusting others, a crucial element as they navigate their journey together.