New comment on reddit

It's called association. Or associative memory.

Remembering a single thing on it's own is very very difficult

But when it is associated with something else (especially something with a major impact on you (eothe positive or negative)), it will stick in your mind better because it now a paired or grouped memory

For example, everyone over a certain age will remember exactly what they were doing when they heard the Twin Towers were hit

Or when Mark McGuire broke the single season home run record

Or when OJ was found not guilty

Or the Berin Wall came down

Or man landed on the moon

In your own life, you will remember what you were eating, listening to, where you were, etc something ”big” happened to you (got engaged, found out your grandma died, got accepted to college, etc)