The thing about writing is that there's no multiple-choice exam you can take to find out if you're doing it right. You know if you're good at math because either you get into the honors classes or you don't... you pass the finals or you fail. With writing, the closest barometer you get in school is to see what kind of grade you get in English class-- or if you're lucky enough to be in a school where "creative writing" is offered (mine didn't offer that), you can check out your grade in that. But it's not objective the way math or science are. Your grade is largely dependent on a single teacher's taste.
A competent teacher can tell you if your grammar stinks, if your writing is full of holes or redundancies, or if you're making common errors-- but there are many areas that teachers can't reliably grade. Your writing style, primarily. Like what I did just there. "Your writing style, primarily" is a fragment, and an English teacher might have red-pencilled it and tried to beat it out of me if I kept writing in fragments. She might have succeeded. Then I would have learned to write in a standard style to please that teacher, but it would have removed some of the flavor from my writing. Sure, fragments aren't technically correct, but that doesn't mean you can't use them in your writing. Plenty of "incorrect" things can be used effectively in your (non-academic) writing.
Some people get so giddy over that fact that they wind up overusing these devices, which is why we have a current crisis of over-perioded sentences, such as:
Best. Day. Ever.
I. Am. Not. Going.
We're just rebelling against our English teachers, see. Someone did it first, and we saw it and thought, "That's so rebellious! Cool! I'm going to try it, too!" And then we all did it, and then it got old, but people kept doing it anyway, and here we are today.
*Tangent: I have just discovered Pandora Radio. Heart!*
Anyway, so we all leave school having only the vaguest notion of whether or not we can actually write, and then we write a short story or an article or novel or some other thing and we try to get it published.
We mostly get a resounding lack of response. We sit by the computer and play stupid games on Facebook to distract us from the fact that 624 editors have managed to utterly ignore that our brilliant masterpiece is sitting right there in their inboxes at this very minute. Putzes.
Then we get some rejections, and we realize maybe we aren't the Best Undiscovered Writers on the Planet, but by golly, someone is going to recognize our wonderful just-shy-of-perfect masterpiece. Right?
And maybe there's a small success along the way to keep us going-- a website that wants to publish something we wrote, or a literary magazine, or whatever. See? we say. We are brilliant after all. By two weeks later, though, we are dirt again. No one notices our success. It was probably a stupid website anyway, one that no one reads.
Maybe we have been deluded about this talent. Maybe we really and truly stink, and those form letter rejections that say patronizing things like "Doesn't fit out list at this time, but this is no reflection on your writing talent" are really written just so the sender doesn't have to feel responsible if you toss yourself off your roof because that was the last straw. Which, maybe, does mean that your writing stinks that much that the editor is afraid you're going to off yourself when you realize it.
Here is where there's a divide. You may then go all anti-establishment and decide you're going to self-publish and prove to those big NY houses what a great thing they missed-- at which point, you'll run off with your trumpet and toot away until you realize that, no, you're not going to be the exception, and the 75 people who buy your book will all be people who are related to you or who work with you. (Cue: despair.)
Or you keep at it and keep at it and eventually find a publisher, get giddy with excitement (see? GENIUS!), sign a bunch of contracts you vaguely understand, while being completely convinced that this publisher thinks you are very special and your book is very special and it's going to be on the New York Times Bestseller List, of course.
Then, 3 months before your book comes out, you realize you don't even know your publicist's name, and shouldn't you know your publicist's name? So you find out, and you e-mail her, and she says enthusiastic things like, "Hello!" and "I'm so eager to work with you!" You love her! Within the next six months, you will hate her. You will think she is probably spending all day painting her nails and talking to her boyfriend on the phone when she's supposed to be out there pitching your special, special book! Does she not like having a job? Surely someone will soon fire her for incompetence, no?
Your book is released and you and your family run all over town to take pictures of it on real live bookstore shelves. Only it's not on a lot of them. You tell the bookstore manager that you wrote this here book and you'd be happy to do a signing here and autograph as many copies as he likes, and he hands you a Sharpie and tells you to sign just two, in case he needs to return the rest. Ouch.
Where is your book tour? Where is your Oprah appearance? The personal driver? The private jet?
Feh. No matter. You will move on, because you are a survivor, and if this book helps just one person...
Oh, who are you kidding? If only one person likes your book, you're going to be devastated. You want thousands of people to like your book. But the professional reviews are... well, where are they, anyway? You lucked out and got one. Didn't that lazy publicist send out your galleys to the others?
She did? Oh. Well, she probably forgot the cover sheet, then.
And you wait for your Amazon reviews, which do come in, but much slower than you expected, and even though they're pretty good, they don't seem to do a whole lot for your sales numbers, which are less than what you had hoped.
And so you're right back to where you started, wondering if you're any good at this writing thing after all. Because if it's a great book, shouldn't people be reading it? Shouldn't they be telling others about it? Shouldn't it naturally rise to the bestseller lists based on merit?
Kinda. And kinda not. There really and truly are great books that don't even get published, let alone make it to bestseller lists. Which is not to say that it's total anarchy out there and the odds are random. No, publishing is still skewed toward those who actually do write good books, thank heavens, but it's not perfect. Some writers get lucky and their books, for whatever reason, wind up attracting lots of media attention. Others remain just as talented but largely invisible.
So it is that you never really know if you're any good. Even the bestselling writers don't know for sure. Many of the top sellers are regularly insulted by writers in the trenches-- partly out of jealousy, of course, but also partly because sometimes popular writing isn't the pinnacle of beautiful writing.
And maybe you hang in there long enough that one day, it no longer matters if you know for sure where your talent lies on the overall scale. Maybe you keep improving and learning and wind up with a loyal following, and you get book deals that make you happy, and you get to spend your career doing something you love and not eating Ramen noodles exclusively. Maybe you learn that you love what you write, and that's enough, too.
All of the things that seem very important for validation when you're at the start of your career will continue to matter to you down the line, too-- but they won't seem so life-or-death anymore. Reviews and appearances and awards and all those things are still meaningful to me because they influence my career options, but that's what they are now: they're part of a much bigger picture. My "forest for the trees" is that I want to have a writing career for the rest of my life, and my ego is fairly irrelevant to achieving that. Do the best work you can. Do work you care about. Find good people to work with. There will be disappointments along the way, but there will also be joys. Cultivate the latter and forget the former. Validate yourself. And not in a dirty way, either. (Perv.)