I've noticed this in myself as well, especially with changes in context.
When I lived in my hometown (until I was 16), memories were always vibrant -- I suppose kept alive by constant association.
After I moved away to college, I gradually started forgetting things from my hometown, even things as recent as my high school years.
After graduating from college, I moved to the countryside in Japan. I found that I started forgetting things about my college years -- even people I hung out with fairly regularly. As for things from my high school or junior high years? Forget about it.
Six years ago I moved to Tokyo; the context change has apparently been enough that I'm forgetting a lot of things about my time in the countryside.
I've always attributed it to a combination of a lack of importance (that is, I consciously or subconsciously decide certain people just aren't important enough to commit to memory) and a lack of associative cueing. Out of all the people I knew in college, I only talk to two -- and them rarely. I don't talk to anyone from high school or before then at all.
When I lived in my hometown (until I was 16), memories were always vibrant -- I suppose kept alive by constant association.
After I moved away to college, I gradually started forgetting things from my hometown, even things as recent as my high school years.
After graduating from college, I moved to the countryside in Japan. I found that I started forgetting things about my college years -- even people I hung out with fairly regularly. As for things from my high school or junior high years? Forget about it.
Six years ago I moved to Tokyo; the context change has apparently been enough that I'm forgetting a lot of things about my time in the countryside.
I've always attributed it to a combination of a lack of importance (that is, I consciously or subconsciously decide certain people just aren't important enough to commit to memory) and a lack of associative cueing. Out of all the people I knew in college, I only talk to two -- and them rarely. I don't talk to anyone from high school or before then at all.