"You're going to have a lot of work to do when I'm gone," Nick Rowswell's mother tells him in the last days of her life. She's right. In a world where millions can die at the touch of a button, erasing one woman's presence from the world is remarkably complicated.

As Nick begins the process of wrapping up his mother's life-her physical remains, her worldly possessions, her administrative existence-he realizes that he never truly knew her.

We know our parents only through the stories they tell-the carefully chosen and well-doctored anecdotes that show them in a positive or humorous...