Definition of "sonder"

sonder

/ˈsɑndɚ/

noun
uncountable
1. (neologism) The profound feeling of realizing that everyone, including strangers passing in the street, has a life as complex as one's own, which they are constantly living despite one's personal lack of awareness of it.
  Quotations
  I had a sonder, a realization that the random girl sitting next to me inside of Starbucks might have a fantastic life or she might be dealing with a very ill family member.
  2012 December, John Buysse, “On 2nd thought, we do have linked lives”, in The Daily Illini, volume 142, number 68,5, University of Illinois, page 4A
  We need to have a "sonder" moment, where we realize that we aren't the only ones with feelings, dreams, regrets and hopes.
  2013, Annie Cohen, "A Deeper Understanding", Panorama (Ladue Horton Watkins High School, St. Louis, Missouri), Volume 62, Issue 3, 14 October 2013, page 14
  I knew the feeling of sonder my whole life. […] Every time I stopped what I was doing and just watched people, this feeling of breathlessness would wash over me.
  2015, Emily Neiman, Sonder: Clara's Story‎, iUniverse