What is a pun in looking for Alaska?

In John Green's novel "Looking for Alaska," a notable pun occurs with the phrase "the labyrinth of suffering." This phrase plays on the dual meaning of "labyrinth" as both a complex maze and a metaphor for life's challenges. The pun emphasizes the intricacies of navigating personal pain and the journey toward understanding and healing. It reflects the characters' struggles and the search for meaning amidst their experiences.