A story that gets read often in classes is Hemingway's "In Another Country". It's a masterful story in its use of understatement and restraint, symbolism, and thematic development.
The story concerns wounded soldiers in Italy undergoing treatment for their injuries. Beneath the surface level, the story is about loss, especially loss of connection to loved ones who sometimes give life meaning. There is also a subtext regarding identity and, we could say, identity as it relates to loss.
One question the story asks is how much we define ourselves through others and how possible it might be to limit this type of dependency.