He talked to me about my work, which he said showed great promise, but he steadfastly maintained that I hadn’t come close to reaching my full potential yet. These words resonated with me very strongly. I think I had secretly felt the same way. I talked to him about how lost I felt, about how I didn’t know what I should do next. His words were simple but powerful: “Make the book you want to make.”
At the time Selznick didn't understand him, but gradually a book unlike any other came into his head, a 550 page long picture book. He had no idea if there was a market for such a book but it was the book he wanted to make. So he did. The result was The Invention of Hugo Cabret, which received the Caldecott Medal, and it's from his acceptance speech that the above quote comes from.
I say to students all the time that they should write from the heart. Creativity has to come from the heart, and not the head. There's no point in trying to write a particular style or for a particular market if it's done for cynical reasons. Everything in writing has already been done - every plot has been covered, every character has already appeared. The only thing that hasn't been done is your story told in your way, with your whole heart behind it.