Your memory keeps the highlights, not a minute-by-minute recording.
That helps explain why a childhood summer can feel enormous while last month seems to have vanished. First experiences give you distinct moments to look back on; familiar weeks can blur together. This is one explanation, not a rule about getting older: attention and emotion matter too. Try naming three moments from last month. The ones that stand out are clues to what made that time memorable. A different walk or a new skill might give this week a few more landmarks.
General information, not a personal assessment. Explore the related articles and sources below.
Why do some years stick in memory more than others?
Think of memory as a map: distinctive moments give you landmarks. A new place, an important conversation, or a difficult challenge can make a year easier to revisit. Routine moments can be vivid too, especially when they matter to you. The useful question is not “Was that year busy?” but “What can I still picture?”