The passage reflects on the passage of time and how memories fade. The author notes how what once could be recalled almost instantly now takes progressively longer to remember. This evokes a sense of loss and nostalgia, as the act of remembering becomes a more challenging and time-consuming endeavor. The imagery of shadows lengthening suggests the inevitable decline of clarity and brightness as time moves on, symbolizing the gradual loss of connection to the past.

The mention of shadows being eventually swallowed by darkness conveys a profound sense of resignation and foreboding about the future. It implies that as time progresses, the memories that once seemed vivid may become entirely obscured. The overall sentiment underscores the melancholic nature of life, where beautiful memories become distant echoes, and the struggle to hold onto them grows increasingly difficult over time.