In displaying the psychology of your characters, minute particulars are essential. God save us from vague generalizations! Be sure not to discuss your hero's state of mind. Make it clear from his actions. Nor is it necessary to portray many main characters. Let two people be the center of gravity in your story: he and she.
Folk-lore means that the soul is sane, but that the universe is wild and full of marvels. Realism means that the world is dull and full of routine, but that the soul is sick and screaming. The problem of the fairy tale is: what will a healthy man do with a fantastic world? The problems of the modern novel is: what will a madman do with a dull world? In the fairy tales the cosmos goes mad; but the hero does not go mad. In the modern novels the hero is mad before the book begins, and suffers from the harsh steadiness and cruel sanity of the cosmos.
What is the end of Fame? 'tis but to fill A certain portion of uncertain paper: Some liken it to climbing up a hill, Whose summit, like all hills, is lost in vapour: For this men write, speak, preach, and heroes kill, And bards burn what they call their "midnight taper," To have, when the original is dust, A name, a wretched picture, and worse bust.