Our subjective experience of time is highly variable. We all know that days can pass like weeks and months can feel like years, and that the opposite can be just as true: A month or year can zoom by in what feels like no time at all.

Foer is pointing to the gap between clock time and lived time: our sense of duration stretches or compresses depending on attention, emotion, novelty, and memory. Periods filled with stress, boredom, or waiting can feel interminable in the moment, while busy or absorbing stretches seem to vanish. Retrospectively, the pattern can invert—novel, information-rich periods often feel longer in memory because they leave more distinct traces, whereas routine blurs together and seems to have “gone quickly.” The quote underscores that time perception is not a neutral internal stopwatch but a construction shaped by cognition, suggesting that how we allocate attention and seek novelty can change how “long” life feels.