Sonder is the realization that each random passerby is living a life as vivid and complex as your own—populated with their own ambitions, friends, routines, worries and inherited craziness—an epic story that continues invisibly around you like an anthill sprawling deep underground, with elaborate passageways to thousands of other lives that you’ll never know existed, in which you might appear only once, as an extra sipping coffee in the background, as a blur of traffic passing on the highway, as a lighted window at dusk. 

Sonder is the profound, individual realization that each person you meet is living their own life, that each person has their own world fitted with their own personal worries, pains, pleasures, ambitions, routines, and joys.

 Sonder is the idea that there are millions of stories happening all at once, around each other, oblivious and contained from one another.