I'm discovering this very truth as I struggle through edits.
Backstory so easily wants to invade those initial pages when you have a hero and heroine rich in baggage. Baggage that has molded them to be who they are at the onset of the current story. Baggage that needs a resolution before character growth can take place.
So how do we get a story to lift off with characters whose pasts scream for exposure early on?
Cut, cut, cut...backstory...no matter how difficult.
Think in terms of morsels. Hints. The reader DOESN'T need to know all!
If a character is becoming unlikeable because of the effects of his/her past, that's when a short nibble of back story put in a dialogue tag or a snippet of exposition is required to hold empathy. But supply just enough to retain the reader's sympathy. Slowly divulge the baggage throughout the whole of the story, so that the current world they live in keeps moving despite how much their past currently drives them.
That's how I'm attempting to fix my back story blunders. How do you go about getting a story firmly moving when the past seems so relevant to everything they do?
Surrendering to Him,