The Law of Diminishing Randomness: As a good story moves forward, the events become less and less random.
One of the differences between real life and a short story is that in a short story, events happen for a reason. In the ordinary world, there are plenty of events that happen in the day that may seem important for a moment, but in the long run are completely meaningless. The telephone rings, and it isn’t a long lost friend. Your car won’t start so you catch a ride from a friend, but as soon as you get to work the day returns to normal. A stranger who appears to be following you turns out to be heading to the same store, but never even realized they were behind you. In the real world, even during times of turmoil or adventure, some events will remain completely unimportant.
In a short story random events are kept to a minimum, and when they do happen, they matter as the story moves forward. A story may open with an accidental meeting, an odd event or a sudden change in circumstances but as the story progresses it is the actions of the characters that drive the plot and lead people to care about what happens. That is why random events tend to happen early rather than late in a story. If the events of the story aren’t driven by the characters then the story had better be about lack of control, because that will be the dominant theme.
In a novel or a movie, there is more room for the random because there is time for sub-plots and minor characters. Not every idea has to have a significant influence on the central conflict of a story. Even with those longer works, however, you will find that random events are focused more at the beginning than at the end.