It's like this: I'm lying awake at night, listening to my husband's gentle breathing beside me, and it happens. A new story idea pops into my head. Thoughts weave together, possible scenarios present themselves, and I fall asleep anxious for morning to come. It does, and once my kids are dressed and fed, and playing happily in their playroom (if you don't have one, I highly recommend it!), I sit down at the computer ready to write. But I can't get more than a sentence or two before hitting that familiar quandary: what do I call this character? Without a name, the person isn't real to me. It's like being at a party full of strangers. You can't really get to know someone unless they come up and introduce themselves. Oh sure, the host might stop by and whisper little tidbits about this person and that in your ear, but they're still people you don't know. You might know a little bit more about them now, but you still don't know who they are, what they wish for, what they fear, what they dream.
For a character to be believable, you have to really get to know them. Understand them. Be them. Even the Evil Mad Scientist will not seem like a real person to your reader unless you know a little bit about what makes him tick. Why does he love science? What caused him to go mad? And when did that madness take on a more sinister bent?
Our name plays a fundamental role in who we become. Hence the popularity of the "information icebreaker" games that hosts often subject their red-faced guests to. "Hello, my name is Sally and I like Scrapbooking." "Hi, I'm Tom and I'm into Transcendental Meditation." That's not to say that every person just happens to have an interest or a hobby beginning with the corresponding letter of their first name, but I think you see where I'm going with this.
For most people, just the mention of a name brings up certain images. Lauren, for instance, is a sweet, attractive, cheerleader-type, while Howard is a businessman whose idea of relaxing is to remove his suit jacket (with the exception of Howard Stern, of course). Jim-Bob is most likely a mechanic with permanent grease-stains under his nails, and Francine, a bubble-gum chomping, leopard-print wearing hairdresser with a southern drawl. Most of us are fortunate enough to be labeled for life with a decent, middle-of-the-road moniker, and for those who aren't, there's always legal name change.
So as a writer, choosing a name for our characters is a big deal. The right one, and the character grows and thrives in all the ways we hoped and dreamed for them. The wrong one, and they might change and develop into someone we barely recognize, let alone should be considered an authority on. And where would our story be then?
Kinda makes you wish they came with name tags, doesn't it?