Final answer:
Collecting new experiences slows down the perceived speed at which time passes because the process of encoding new experiences into memory and consolidating them into long-term memory makes time feel more drawn out.
Step-by-step explanation:
The question of why collecting new memories seems to slow down the perceived speed of time involves concepts of psychology, particularly concerning how memories are formed and recalled. When we encounter new experiences, time dilation in a psychological sense occurs because the process of encoding new information and the subsequent consolidation into long-term memory requires attention and cognition, making time feel more drawn out.
Within the context of forming memories, the phenomenon described is not the same as the physical theory of time dilation related to relativity, where time literally passes slower for a moving observer compared to one at rest. Instead, the psychological perception of time slowing down is tied to factors such as the decay of memory traces and interference, which affect how information is retained over time. A full and active day packed with diverse experiences can feel longer in hindsight compared to a monotonous one, mainly because more memories need to be consolidated.
Storage decay and interference, like proactive interference, can lead to memories fading, thereby contributing to the experience that time is moving differently when we reflect on the past. The effort to form and consolidate new memories, especially if they are significant or require complex processing, may be partly why we feel time is extended during periods of new experiences.