After seven best-selling books spawning eight movies and two (soon to be three) theme parks, you would think that JK Rowling never faces rejection in her writing. You would be right. JK Rowling has never faced the sort of rejection she got with "Harry Potter and the Sorcerer's Stone"; but Robert Galbraith did.
For those that have been living under a rock since December 21, 2012; the world didn't end, and JK Rowling was revealed as Robert Galbraith in early 2013.
Rowling aka Galbraith faced a mountain of rejection upon sending her/his manuscript to several publishers in the UK. One even took it to the level of explaining to her/him how the publishing business works.
Even JK Rowling has her insecurities. Why were those publishers turning Galbraith down? Was JK not a good enough writer? Had she lost her touch since "The Casual Vacancy"?
After milling through publisher after publisher, Robert finally got his book published. It sold marginally well until it was revealed Rowling and Robert were one in the same. Then it exploded.
Rowling supplied this tidbit of advice to all amateur writers.