Sometimes I am in the middle of a conversation in a story and I realize that one response from a character could turn the whole conversation in another direction. New things could be exposed from one word, from one thing the other character chooses to focus on.
Will he point out that she didn't finish one of her sentences? Will she choose to focus on what his words imply? And you'd think that as the writer I have full control but I don't. Responses could lead to an infinite number of possibilities depending on what occurs to me first, just as it happens in real conversations.
One moment has the possibility of blooming into a thousand different stories. But isn't that the way real life works too?