Broken Memories

Think of a favorite memory. Perhaps it was your first kiss, a game-winning shot or the birth of your child. Now ask yourself, what's it worth?

The best memory is typically a shared experience, a phenomenon greater than the sum of its parts. The kiss is memorable for its passion, the shot for its joy and the birth for its life.

The appreciation of a memory often comes from its reliving with a shared party. But when that other loses the memory, does its value change?

Every day I invest in precious moments destined to be forgotten. I have two young daughters. My toddler will likely never remember saying I looked "broken" when I danced, and my infant surely won't remember her hectic birth in an ambulance.

Modern neuroscience suggests it's impossible to remember much of our first two years. The average earliest long-term memory doesn't appear until three and one-half, in part because we can't make sense of early experiences.

However, a recent study proposes a new explanation. Using mice, researchers show that by continually adding neurons, the brain disrupts older memories. In other words, as the brain grows, old memories are broken down to make room for new ones. Since brain growth peaks in the first three years, this might explain why we can't remember our early childhood.

Perhaps some memories are not meant to be preserved but molded as one sees fit. When I see images of my childhood, I don't remember the young beauty in the red sundress or the hip dude with the big collars and sideburns, but it's enchanting to fantasize about who my parents were.

My precious memories of my daughters' first years will surely persevere in some form. I find it comforting to think that, in a few years, my daughters won't remember my broken dancing. Without photo evidence, I'll tell of how light on my feet I used to be -- a simple fix for broken memories.

With a Perspective, I'm Niall Kavanagh.

Niall Kavanagh is a research associate at the Veterans Administration Palo Alto. He lives in San Francisco.