Short, but I hope it is good. Credit to barblibrarian for inspiration for the last two points.
Bonne lecture.
Mr Darcy has been to Eton and to Oxford. He has had the best of private tutors, and advisors whose monthly wages rivaled what most men were paid annually. He has travelled extensively, met countless people, and read scores of books.
Yet no amount of book-learning could have prepared him for marriage to Elizabeth. The education of a husband is unlike anything he expected. His lessons are many, and sometimes difficult.
He learns that she is lively, sometimes too lively, and at ungodly hours of the morning.
He learns that she does not like to be ignored, that he must make some response—any response—if she speaks.
He learns that she despises to remain indoors, even while ill.
He learns that she despises even more to be told what to do, most certainly by his—to use her term, spoken in the most sarcastic voice he has ever heard—"most august and wise personage!"
He learns that if they argue, he should not touch her in any way, lest she accuse him of trying to seduce her out of her black temper.
(He also learns that, if he is careful about it, he can seduce her out of her black temper, though he ought never to mention that.)
He learns that she is not the sort of person to unfairly distribute anger. If she is vexed with him she will still treat Georgiana with the utmost kindness—more, perhaps, to make up for having such a—again, her term—"proud, dreadful brother!"
He learns that she is not the sort of woman to exclaim over flowers and jewels, but that a gift of a book or a long walk on the grounds will send her into high glee.
He learns that she often mocks what hurts her, as she had done when he had first remarked upon her appearance, and that while others laugh at her mimicry, he can always catch her eye and give her a comforting smile, and receive a grateful look in return.
He learns that when she is angry with him, she will call him Mr Darcy; when she is exasperated, Fitzwilliam; when she is pleased, William; and rarely, very rarely, when she is in high spirits, the startling (and oddly endearing) Will.
He learns that she very much likes the sight of him unshaven (though the thought of what usually follows makes him blush).
He learns that she is not jealous, not even when Miss Bingley flirts outrageously with him every time she visits Pemberley.
He learns that he, to his surprise, is extremely jealous, when a certain colonel cousin of his comes to visit and charms endless laughs from Elizabeth.
He learns that she will flush with pleasure every time he calls her Lizzy, for he is seldom so comfortable to do so.
He learns that they cannot be madly in love all the time, for there are days when his pride returns to him, and her prejudice returns to her, and each wonders why they are married.
But mostly, he learns that while they cannot be madly in love all the time, they can, simply, be in love all the time, and that, he thinks, is the most important lesson of all.