I've had a few failed novel attempts over the years. Let's take a look at a few:
"My Mother is a Monster": Conceived of during my teenage years, this tale was about a 16-year-old who has to deal with such horrors as her mother insisting she come home by curfew; the cruelty of her mother refusing to let her out of the house in a skirt that barely covers her butt; and the worst of terrors, her mother insisting on calling her friends' parents to make sure the party the poor girl wants to attend will be supervised and that no alcohol will be served. It turns out that probably all of these things were for the main character's own good, but it took me a few years and a few failed agent queries to figure that out.
"Lame-o, the Sheepish Werewolf": In my early horror-writing days, I thought it would be fun to write about a werewolf that generally spent his days sunning himself on a rock, and preferred to eat Friendly's chocolate peanut butter sundaes over people. The terrifying part, of course, would be when Lame-o discovers he's lactose intolerant. However, it turns out there isn't much of a market for a non-snarling, dairy-loving werewolf named Lame-o. Live and learn.
"Zombie A-p-o-c-a-l-y-p-s-e": Sure, we all know that to survive the apocalypse of the undead, one will have to have some basic skills: hunting, gathering, finding weapons, using those weapons well, and, of course, the sidekick that always gets asked "how do you spell...?" Kept around for his impeccable spelling and grammatical abilities, Theodore hangs out with Butch, Fang, and Eyeball, letting them decapitate zombies and disembowel ghouls, while he reminds them that the decapitations are having a negative effect, not affect, on his appetite. This story was humming right along until Eyeball killed and ate Theodore in Chapter Three. Rule of thumb: never trust a character named Eyeball. Had I known he was a cannibal when I started writing the book, I never would have let him live past Chapter Two.
So remember, aspiring writers, not every idea is agood idea. And when you show your first draft of your novel to your family and your mother says "you have a LOT of nerve, young lady! You're grounded!"...well, then, maybe it's time to explore new ideas.