You cannot hope to sweep someone else away by the force of your writing until it has been done to you.
Grit, experience, whatever you like to call it, is an essential component to writing an authentic book. Can you be authentic, even in fiction, if you haven’t experienced whatever it is you’re writing about? Oh sure, but you’d better put on your researcher’s hat and get your nose in some dusty old books. Otherwise, the reader will not trust you. Don’t phone in it. You have to experience, to draw from that experience if you want to produce a believable story. This is the reason there are very few child writing prodigies. Oh sure, there are some, but even these kids have experienced the true grit of life. Experience forms us, inspires us, pushes us to exorcise the demons and place them properly on the page. Heartbreak at a young age? The death of a parent or partner? An illness you’ve survived? These are all key factors, true experience, that will cradle and nurture an authentic story.