Especially if the book your writing is part of a series and even more so if you're placing it within a fantasy world of your own making. Also, learn from my mistakes: don't write such a story and then make up your own races and then on top of that create 30+ characters to live within that world that you know you'll be interacting with on more than just a 1 page basis.
What brings this on? I'm into my third book, probably a little over half-way done writing it, and I'm in a battle scene. Normally these are really fun for me. Battle scenes are where most of the images in my head come from. But this one is really difficult, and I kind of always knew it would be, I just never wanted to admit it.
I've got around 25 of the 30+ characters I've created in this battle, and that's what's making it so difficult. See?

That's everything that I have open on my computer as I write a battle scene for this current situation. Most of what's open right now are word documents. I even created a whole word document that analyzes where my characters are and has a table to allow me the ability to strike through everyone that we've seen so far in the battle. You see, the problem with only mentioning two of them throughout the whole ordeal makes it sound like it was only two people involved in the battle. That doesn't make it believable when you've got over 20 characters running around in said fight.
Writing is a task that takes hours of blood, sweat and tears. Anyone who tells you it's an easy process has never actually attempted it or is in denial. Even more so when you take into account the kind of world we live in today.
I could, if I wanted to, self-publish my book right now. I won't, because there's a lot left to edit before I even pursue publishing. But because anyone who ever sits down and decides to open a word document and write a 100 page story can post their book online and sell it for whatever they want. Because of that, we run the risk of people uploading crap that is still on its first draft sitting out on the internet for unknowing buyers to fill their libraries with.
There's a very real risk for lots and lots of bad writing to get out into the world. Now, in theory, only the good stuff will become popular. But that just isn't the case anymore. If enough hype is brought up around a series (or even one book), it can mean little to nothing if the story is well constructed or the writer in question can spell or properly construct a sentence.
Anyway, I'm going to go back to writing for a smigin before I call it a night/morning. I've got my last day of classes tomorrow and I need to be somewhat coherent. I do have a presentation in my Ceramics class first thing in the morning.
Currently Writing: End Game: Trinity (Chapter Eighteen)
Currently Reading: The Time Traveler's Wife
Currently Listening to: "Enigmatic Soul" by Two Steps From Hell