Well, it could be about freedom. Just like a breath of air is liberating, the story might revolve around a character achieving freedom in some form, perhaps from a difficult situation or a restricting mindset.
There could be a young character in the 'a breath of air short story' who is feeling trapped in their current life. And then there might be an older, wiser character who comes in and through their actions or words, provides that 'breath of air' moment for the young character. It's possible that these two are the main characters.
The book 'When Breath Becomes Air' is a poignant tale that follows the author's battle with illness and his quest for understanding the significance of life and the practice of medicine. It offers a raw and intimate look at one's confrontation with death and the search for meaning in the face of it.
Definitely non-fiction. The book offers an intimate and honest account of the author's journey facing a terminal illness, making it a true personal narrative.