When dose a writer often reveal an implied universal theme in a story?

Introduction to making a difference: it’s our world, too

Hillenbrand writes, "as louie blazed through college, far away, history was turning" (p. 43). why does the author interrupt louie's narrative with information about japan and germany?

Excerpt from jane eyre charlotte bronte 2 i was glad of it: i never liked long walks, especially on chilly afternoons: dreadful to me was the coming home in the raw twilight, with nipped fingers and toes, and a heart saddened by the chidings of bessie, the nurse, and humbled by the consciousness of my physical inferiority to eliza, john, and georgiana reed.