I am entering the Age of Subtraction. Almost as if there existed an imperceptible fulcrum I had to get over, and I’m now finding myself sliding on the downside. So much of adult life until now was about Addition—collecting experiences and perspectives—countries been to and books read, bands seen—and then a husband and family and…

I am reading a biography of the theologian Dietrich Bonhoeffer, who was hanged in 1945 for his role in the plot to kill Hitler. Suddenly the door opens and my two-year-old grandson, Alex, bounces in. Seeing the book, he attempts to climb into my lap so I can read to him as well. I put…