There are many common themes in literature that have become so overused, watered down and taken lightly that they eventually transform into a trope or a stereotype. If you are to read classic literature, you can often find the origins of these tropes in a classic story, and somehow those classics rarely feel so overused as their modern counterparts do.
For example, there are several forgettable war/love movies set in WWII, but the further along we get the more forgettable they get. However, if you watch “Casablanca,” you suddenly realized how a story like that could spur an entire genre of film. Alternatively, many cliché action movies were born from the legitimately good “Die Hard” film.
Hemingway, who had served with the Red Cross during WWI and been seriously injured, could be described as one of these primary sources from the overused: “I’ve seen war therefore I’m inevitably traumatized and unable to function in society” trope that plagues many books and films today. However, if one goes back and actually reads his books, they’ll find that he dives so much deeper into the subject, heading beyond the dismissive idea that war is simply some hazy disease that soldiers catch when they go overseas. His description of the aftermath is not that of helpless victims — it is not about the victimhood at all — he simply just describes a heavy weight and the ways that people carry it. You can see this in “In Our Time” and you can also see it in “For Whom the Bell Tolls.”
“For Whom the Bell Tolls” revolves around an American “dynamiter,” tasked with working alongside Spanish locals to demolish an enemy bridge at a specific time, so as to support friendly troops and cut off enemy reinforcements. It’s a very Green Beret type story, set during the Spanish Civil War.