First, a little tip of the cap to Nathan Bransford, for his post today, which is right on track with how I happen to be looking at and working on my own writing projects right now.
Last week I started really digging into a third draft of one of my WIPs. This round involves heavily paring down a lot of superfluous bits of the first two drafts, from settings to world building to whole characters that aren't going to be strong enough or important enough to the story to leave them all in. I'm a noted panster, and I love working on first drafts, where all the ideas can just pour out into one big bucket of book soup. The real work is in slowly simmering that vat of words down into a tasty, manageable, and most importantly enjoyable treat of a novel.
Sometimes characters leave your book, and you easily forget about them as you revise. And sometimes characters are important, but must stay mostly in the background. For instance, almost all parents in middle grade fiction. Of course there are exceptions, and parents who play a larger role, but in so many children's stories, the parents must be predisposed in order to serve the plot. Which makes perfect sense, as so many tales couldn't happen if anyone's sensible mother or father was paying attention to the children in the first place. The story isn't about the parents, except for the background they provide to the protagonists. Mom and Dad remain largely off stage while the kids get to be the stars of the show, and I have no problem with that. Except that another manuscript of mine includes a set of parents with a really fantastic backstory that has no place in the book itself, and their epic relationship will probably remain just a collection of notes in one of the dozens of books of other notes about the story of another character.
One of my favorite plays is Tom Stoppard's Rosencranz and Guildenstern are Dead, which explores the perspective of two minor characters from Hamlet as the events of the main story unfold around them, with hilarious results.
Unfortunately, not every character in every story can have their whole tale told in full, or even expounded upon Stoppard-style for a few hours trespass of the boards. But I can say, just as with Hamlet's dear departed schoolmates, my unsung characters' biggest mistake was getting on a boat.