How do you explain the visceral and personal pain caused by the killing of a black person you did not even know to people who did not grow up with, as their legacy, the hushed stories of black bodies hung from trees by a lynching mob populated with sheriff’s deputies? Or of law enforcement, who often doubled as the Ku Klux Klan, killing black Southerners on lonely roads under the gaze of a silent moon?

To many of us, the almost guaranteed failure in modern times to hold the police responsible for these deaths feels eerily familiar; black Americans add these recent cases to the list of countless black people who died a few generations ago “at the hands of persons unknown.”

But, of course, this is not just about history and our disparate recollections of it. It is about now, and the way the vast gulf between the collective lived experiences of white Americans and that of black Americans can make true empathy seem impossible.

How do you explain — how can you make those who are not black feel — the consuming sense of dread and despair, when one sees the smiling faces, captured in photos, of Mr. Castile and Mr. Sterling, and knows that but for the grace of God, it could have been your uncle, your brother, your child, you? That if a police officer, his mind having soaked up centuries of racial fears, were to stop your loved one, or you, he may not be able to see a family man or doting mother? Someone who is not a boogeyman, but someone whom, as Ta-Nehisi Coates so piercingly lays out in “Between the World and Me,” parents, aunts and uncles, grandparents, spouses, children and community had poured their love, hopes and dreams into. Someone who pushed a daughter on the swing, hugged a fiancée after an argument, told bad jokes.

How do you explain that awful understanding that each of these deaths confirms for black citizens, that if stopped by the police, we may be stripped down to our most basic of elements, that one part of us that is a complete fiction: our race. And that fiction — the American crime of blackness — can turn a broken taillight into a death sentence.

The last thing I wanted to do that day, and on many days, was face people who did not, at a gut level, get this. My friends, also struggling to leave their homes and head out into the world, reached out to me, and I to them. We sent texts and Facebook messages. We grieved together, trying to fill the hollow with love. Many people called into work that day, unable to deal with the mundane in the face of a tragedy.