Be humble for you are made of earth, be noble for you are made of stars.
This sentence has five words. Here are five more words. Five-word sentences are fine. But several together become monotonous. Listen to what is happening. The writing is getting boring. The sound of it drones. It’s like a stuck record. The ear demands some variety. Now listen. I vary the sentence length, and I create music. Music. The writing sings. It has a pleasant rhythm, a lilt, a harmony. I use short sentences. And I use sentences of medium length. And sometimes, when I am certain the reader is rested, I will engage him with a sentence of considerable length, a sentence that burns with energy and builds with all the impetus of a crescendo, the roll of the drums, the crash of the cymbals–sounds that say listen to this, it is important.
Stories you read when you’re the right age never quite leave you. You may forget who wrote them or what the story was called. Sometimes you’ll forget precisely what happened, but if a story touches you it will stay with you, haunting the places in your mind that you rarely ever visit.
— Neil Gaiman (M Is for Magic)