There is a point in most writer's career when they realize... they don't crave that external validation like they once did.
No, it doesn't come when you hit the NYT Best Seller list. I mean, maybe it does. I haven't gotten there yet, but I'm sure it's an awesome feeling either way. Regardless, it doesn't have to take accomplishing a milestone like that to have it hit you.
When most writers start out, I think we all have that same feeling of nearly crippling insecurity. It sounds something like this ...
Is my writing good enough? Will anyone want to read it? Will my friends laugh at me if I tell them I'm writing a book? Am I totally crazy for thinking I can write more than my name?
Then, as you get more serious about writing, it changes to ...
Can I get this published? Would an agent even be willing to entertain the idea of signing my ramblings? Why would anyone ever read one of my books when there are writers like Janet Evanovich out there cracking people up on a regularly basis?
Then as you start submitting to agents and publishers and the rejection letters begin to pile up and your manuscript is gathering dust, that's when the panic begins to set in. It sounds something like this ...
WHEN will I get published? How do I make agents take me seriously? Why won't someone look at my book? What is wrong with my writing? Why don't people like my stories? Why don't people like me?
Seriously, you start to feel like every rejection of your book is a rejection of you. You think you must be doing something wrong, but you have no clue what it is. We lose a few fellow writers at this point, but in general we're a persistent bunch, and we keep trying. We think everything will turn up rainbows and lollipops when we finally land our first contract. Then it HAPPENS ...and then we start to sound like this ...
Why isn't my book selling better? Why isn't my publisher doing more? Who designed that awful cover? Is there an editor alive who actually knows how to edit for real? When will I finally get paid? Marketing sucks! This is way harder than I thought it would be. Noooo! I got a bad review!!! Why doesn't everyone adore my book?
Writers spend years riding the roller coaster that is the world of writing and publishing. We go from emotional basket cases to deliriously over the moon to spitting mad at everyone involved in producing a book.
There is a point when all of the frustration and agony you have been through suddenly doesn't matter anymore, because you realize you aren't crazy for wanting to be an author, and it doesn't matter if a few people don't like your writing (readers, agents, and publishers included), and you don't need that constant external validation from other people to understand that you know what you're doing.
You've been at this long enough to know that you're a good writer. Whether an agent thinks your topic is derivative, or a publisher says they already have enough of what you just spent the last year pouring yourself into, or a reader thinks you're just writing Twilight knockoffs, you know that your stories have merit and will have an impact on the people who read it, and suddenly, that's all you need to know.
Getting praise and great reviews is still fabulous, but being able do what you love is just as rewarding. If a publisher doesn't want your book, that's okay, because you have other options. You don't need them to tell you your book is good. You already know that.