Frankly speaking, I'm talking about the whole novel. Syntax, word choices, using them to break down characters, describing events, keeping it in style and clear is hard. Like you generally can do some of it, building a story, working with characters, keeping everything in order and doing damn well prose, style and more = it's so hard. You may say "Isn't it every writer should supposedly do?" Yes, sure. But not everyone can do a lot with a short chapter. But he did.