Poking around with a character's backstory and found it ramifying.
And NOT in support of the story. Just happy little incidents in her happy childhood, few of which will even have a chance to affect the future. Maybe some characters will re-appear, but old home week does not move the story forward.
Not to mention NOT in creating a new beginning of the story -- the drama still starts when it starts. (Hmm. Maybe a LITTLE earlier.)
Though I did manage to get one hint by having her babble of something that happened to her, making her the expert when the same monster shows up. (Expert: the person who saw the monster once before.)