Thickening the Plot
Imagine, if you can, that while Homer is outside loading the station wagon, Marge is inside talking with Lisa, who doesn't want to go camping at all because she has a saxophone concert on Sunday afternoon. "Don't worry," Marge assures her, "we'll be back in plenty of time." Now we have two stories, in a sense separate, yet intertwined like braided strands of rope.
Every individual story is made up of other stories that overlap and interconnect.And while this example is fictional, real life works that way, too. Every individual story is made up of other stories that overlap and interconnect in interesting ways.
If you notice these strands and see how they relate, you can use them to add texture to your essay. You can shift focus like a movie camera from one story to another, letting the reader see how the stories entwine.