Most of my newsletter readers know I'm a fan of old letters, diaries, and journals. These source materials are invaluable to me as I create relatable characters who face challenges, live through sorrow and betrayal, struggle with doubt, and act on their aspirations to achieve flourishing lives.

My godmother's diaries are an inspiration—seventy years of journal writing every day! Her diaries (and others) give me insight into long-forgotten challenges—like the entry: Wed. Feb. 20, 1924: Smallp...