Presenting master teacher, editor and Assoc. Publisher at Dutton Children's books, Julie Strauss-Gabel:
There is no such thing as "mine". A book is a collaborative experience. It's usually understood that publishing is collborative...but so is reading. If your goal is to be published -- to be read -- readers are always going to bring their own interpretive lens to your words; it now belongs to them. Some may disagree with you. Some may not want to keep reading. The only control you have over what they take away from your book is to build an irresistible and convincing world on the page.
Not all readers (including those in the business, from agents and editors to reviewers) are great readers. We're not always right, or the right fit. Learn to interpret and blance the feedback and direction you receive, but always listen. If someone sees something different, or misses something you consider important, ask yourself why. Ask yourself what you have failed to translate onto the page. Don't immediately dismiss it. Don't see it as a threat or as someone taking away what's yours.
Especially for new writers, few things dismay me as much as the anonymous message board/blog chorus that reinforces the idea that there's some singular, holy ownership of a story -- an absolute, correct Mine. Just as a critique gorup that does nothing but pile on praise might feel great for five minutes but do nothing to advance your work or your career, shutting out criticism and shutting down new ideas never helped anyone to grow.
Embrace the possibility of change and find your own solutions -- solutions true to your voice and your talent -- when people challenge you to take your work to the next level. It's the difference between published and not published, between one sale and a career.