Neither is it necessary (or desirable) to put all your planning of the background of your story actually into the tale itself. It is better to drip feed information the reader really does need to know to make sense of the tale but to avoid doing this all at once. It should be a gradual realisation.
I think the more you the writer know of your story background the more convincingly you'll write about it but there does come a time when you actually have to write the tale and the background research has to stop.