Our perception of time is heavily influenced by how many new experiences and memories we create; childhood is rich with 'firsts,' while adulthood often becomes more routine.

When we're young, almost everything is new. Every day brings a 'first time' – a new word, a new game, a new friend, a new place. These novel experiences create strong, distinct memories that act like mental markers. The more markers we have, the more 'filled' a period of time feels in our memory, making it seem longer when we look back. Think about a vacation: it feels longer because it's packed with new sights and sounds. As adults, our lives often settle into routines. We go to the same job, do similar tasks, and our days blend together. Fewer new, distinct memories are formed, so when we recall a month or a year, there aren't as many 'markers' to grab onto. Our brains effectively compress these routine periods, making them feel like they flew by.