In my opinion, the difference between good writing and great writing is personality, or what we sometimes refer to as voice. A good writer can inform you or entertain you, a great writer can make you feel a part of the story.
In order to involve your reader, you need to make them care. To make them care, you have to write in such a way that you connect with your character and can share that experience. In order to share that experience, you’ve had to have had that experience yourself.
I know what you’re thinking: Does that mean Tolkien really travelled to the Middle Earth? Don’t be ridiculous, one does not simply walk into Mordor.
Like Tolkien though, you need to immerse yourself into the world you are writing. If the underlying heart of your story is fear, then you should include your own fears. If it is about hope, then share your hopes. If your story is about losing your hat, add the emotions and thoughts you experienced during a time of your own loss.
That is what it means when you hear agents and editors say to write what you know. They aren’t expecting you to be an expert, they are expecting you to bring your passion and experiences, even when it comes to nonfiction.
I don’t think Candace Flemming has ever dived deep into the ocean to study Giant Squid, but she captures the experience beautifully in her book. I am sure that Jason Chin is not an expert of the Grand Canyon, but you can see his experiences come through on the page.
When I wrote Pedro’s Pan: A Gold Rush Story, I included tidbits from my own experiences growing up prospecting with my dad. I drew on the fears I had of what everyone else expected me to be and the fear of failing them.
It is a fear that I still have, a fear that I believe all authors have: the fear of being a fraud, of not being who we think everyone else sees us being. What if I don’t have another book, does that mean I’m really an author? Am I broken? Am I failure?
So as you write, think about what you can personally add to your story. How can you draw on your own experiences to show the deep desire or disappoint of that little girl who really wants a unicorn? How can you draw on your own life to express the pride of a snail who completed his great garden journey? Or the fear of someone who knocks on the door of the creepy house down the street without knowing what is on the other side?
In the end you will find that when you write well, you will leave little pieces of yourself in the stories and in the characters and when you do, that is what your reader will connect with.