Tim Keller is his excellent book on marriage The Meaning of Marriage makes the shocking (to some) point that we never know who we marry. Once we bring two people together in such intimate closeness, they change each other so that the one we find ourselves married to in three or four or forty years is never quite the same person to whom we said ‘I do’ at the ceremony.
Poet and author Kathleen Norris makes a similar point in her memoir Acedia and Me: A Marriage, Monks, and a Writer’s Life. After telling the story of how her husband came close to a drink-induced suicide, she says this:
Like faith, marriage is a mystery. The person you’re committed to spending your life with is known and yet unknown, at the same time remarkably intimate and necessarily other. The classic “seven-year itch” may not he a case of familiarity breeding ennui and contempt, but the shock of having someone you thought you knew all too well suddenly seem a stranger. When that happens, you are compelled to either recommit to the relationship or get the hell out. There are many such times in a marriage. (Page 83)
Long married couples understand this and agree. Engaged couples with whom I share it shake their heads up and down but really don’t believe me. They will.