Our lives are the sum of our memories. How much are we willing to lose from our already short lives by … not paying attention?

Foer links identity and lived experience to memory: what we remember is, in effect, what we have “lived,” because memory is the medium through which experience becomes part of the self. The second sentence turns this into an ethical challenge about attention. If distraction prevents experiences from being encoded and retained, then inattentiveness doesn’t merely waste time in the moment—it erases portions of life from the narrative we carry forward. The quote thus frames attention as a form of stewardship over one’s finite life: to notice, encode, and revisit experience is to preserve it; to drift through it is to forfeit it.