This article by Katy Waldman at Slate looks at the reasons why our twenty-something years create such vivid memories compared to the rest of our lives.
A little-known but robust line of research shows that there really is something deeply, weirdly meaningful about this period. It plays an outsize role in how we structure our expectations, stories, and memories. The basic finding is this: We remember more events from late adolescence and early adulthood than from any other stage of our lives. This phenomenon is called the reminiscence bump.
Spoiler: The answer seems to be that we’re more likely to remember things from our 20s because that’s when we’re also forming a self-identity. That’s the time in our lives when we get our first apartment, our first jobs, meet our future spouse, etc. This makes sense if the person you decide you want to be at 23 is the same person you want to be the rest of your life. But I feel like the identity I formed at that age is nothing like the identity I have now. Will I remember time I spent as a stay-at-home dad, going to grad school and starting a new career more vividly than when I was a 23-year-old, overgrown frat boy living in Lincoln Park? I sure hope so.