When Henry describes what the Dionysian ritual felt like the first time it truly worked, he uses a hyperbole to illustrate the true ecstasy of his existence in that moment:
It was like a film in fast motion, the moon waxing and waning, clouds rushing across the sky. Vines grew from the ground so fast they twined up the trees like snakes; seasons passing in the wink of an eye, entire years for all I know […] Time is something which defies spring and winter, birth and decay, the good and the bad, indifferently […] You have no idea how pallid the workday boundaries of ordinary existence seem, after such an ecstasy. It was like being a baby. I couldn’t remember my name. The soles of my feet were cut to pieces and I couldn’t even feel it.
Henry's description of the ritual hyperbolizes the speed at which time passed, pointing out the impossibly fast changes of phase of the moon and the temperament of the weather. The seasons passed in what felt like "the wink of an eye" to Henry. Everything was moving so fast, yet nothing was changing in reality. Henry even compared the feeling of ecstasy and purity he experienced during the Dionysian ritual to being a baby, a period of time in someone's life where time and identity are completely irrelevant. This is the type of wildness and freedom that the Greek students had been searching for by performing this ritual.
Additionally, these hyperbolic descriptions of perception give Richard a glimpse into what the group experienced that night. Doing so allows Richard to understand the group's actions and behavior, thus providing justification for Bunny's subsequent murder.