Beloved

If I could give one piece of advice to young brides, and only one, it would be this: study your man. Study him as if he were some rare and strange and fascinating animal, which he is. Study his likes and dislikes, his strengths and weaknesses, his moods and mannerisms. Just loving a man is fine, but it's not enough. To live with one successfully you have to know him, and to know him, you have to study him.

Look around you and decide how many of the best marriages you know are ones where a wife in a deep sense actually knows her husband better than he knows himself. Knows what pleases him. Knows what upsets him. Knows what makes him laugh or makes him angry. Knows when he needs encouragement. Knows when he's too charged up about something and needs to be held back. Knows, in other words, exactly what makes him tick.

- Mrs. Norman Vincent Peale, The Adventure of Being a Wife
(Englewood Cliffs, New Jersey: Prentice Hall, Inc., 1971) pg 29.

Think it probably applies both ways. But I like the use of language here.