In Jeffrey Eugenides' "The Marriage Plot," the concept of time perception is explored through the lens of age. When a child is five years old, each day feels significant because it represents a substantial part of their short life, making time seem expansive. This highlights how youthful experiences are often vivid and memorable due to their novelty and the limited number of days they have lived.

Conversely, by the time a person reaches fifty, the accumulation of experiences gives each individual day less weight in the context of their entire life. With roughly twenty thousand days lived, a single day appears to hold less importance, leading to a perception that time passes more rapidly. This reflection invites readers to consider how perspective changes with age and how our relationship with time evolves throughout life.