It was the characters' personalities themselves. Now, I love all three of my main characters, and I've written down their personality traits, loves, hates, wishes, etc. I thought this would be enough impetus, depth, to give me enough of a comfort level to be able to hop into their heads and take on their personalities.
It was easy at first while rushing through Nanowrimo and not worrying about being 100% perfect, after all the point of Nano wasn't to have a perfect draft, but to have one, period. I did that and I loved the story that flowed from my fingers and onto the page (but not, if anyone remembers, the title or synopsis...they just didn't do the depth of the plot justice).
I even began editing/revising and fixing those cringe worthy typos and grammar mistakes. In doing so I began to realize just how unfocused the story's "voice" was and it took me another few weeks to realize that three voices, three characters to head hop in, were too many. So I redid the entire first chapter in one character's voice, in first person POV, and it just...worked. So why would this huge switch make such a big deal, what about their personalities, their motivations, the plot, make such a huge difference?
It was the characters themselves. They all but told me, humbly, that I needed to focus on the one character because her voice was the smallest and would have the greatest impact on the entire story overall.
What about her though and why? First of all she is the exact opposite of me. She is a challenge to write and that is the kind of challenge I rise up to. Her story is not a pretty one, not the fun and flowers, Daddy's Princess childhood, while mine was almost that and I got to do things, albeit my own way (Never was a fan of overly girly things...I used to catch snakes out in the fields and stuff them into canning jars to show my parents proudly, rode motorcycles, and pretty much flunked out of Ballet.) So by being my polar opposite I felt I knew her even better.
I kept her character sheet the same, but with the first person angle I began to get to know her, almost as if she was writing the words, just using my fingers to translate them down onto the page. Did she have moments that startled me, quirks? Heck yeah. I'd even sit after writing a section and wonder just how she managed to possess my fingers and delve deeper into who she was without me consciously planning to write it that way.
Now, what about the other main characters? Would they be shoved into lesser importance by focusing on her? Or would her POV give them the needed impetus to be better characters, to show not just the reader who will eventually read the book, but me the writer, parts of their personalities, their stories? Would being filtered through her make them more lovable, more frustrating, more brave, more sad, more honest (I say honest with a hitch, not that they'd be dishonest characters, but honest with themselves and their feelings, their beliefs)?
I have come to love these characters and while their personalities haven't changed, the ability to express, to show them, to push me to write them better, has.