A short story is a piece of imagined life taken out of the flow, so to speak, and given a special cut and polish, a reader can still be made aware of the flow.
The story can be seen to fit into life as-a-whole. It can and normally should imply before-and-after, and also perhaps a context. Admittedly it should not present 'truth of a human life' in a general way; it can seldom hold enough material for generalization.