I'll add to this by offering "even a good marriage is like combat. countless hours of boredom separated by moments of raw abject terror"
But the rewards are out of this world!
My marriage started with a blind date, being told by her "If you touch me before marriage you will lose a hand and me!" and she started with me saying "I'm a Borne Again Christain and do not believe in sex before marriage!". 11 months later we were married.
We celebrated 18 years last Sunday (9-11). There have been some rough times but the "D" work has never came up, and we can both honestly say we are more in love today than 18 years ago. The biggest reason we get along so well? I can't post it as it could be a rule violation (discussion of religion), but I will say it is the main comman element in our relationship.