Raymond Carver writes an extraordinary description about short stories:
I once sat down to write what turned out to be a pretty good story, though only the first sentence of the story had offered itself to me when I began it. For several days I’d been going around with this sentence in my head: “He was running the vacuum cleaner when the telephone rang.” I knew a story was there and that it wanted telling. I felt it in my bones, that a story belonged with that beginning, if I could just have the time to write it. I found the time, an entire day �12, 15 hours even�i f I wanted to make use of it. I did, and I sat down in the morning and wrote the first sentence, and other sentences promptly began to attach themselves.