re: How is it that loving married couples end up hating each other so often?

I don't think "hating"each other is the killer; it's when one or both stops caring enough enough to love/hate the other. For us, marriage is repeatedly choosing to love each other even when we're not very lovable. We were blessed that we lived 5 hours away from immediate family during the first years of marriage. Running home to Mama wasn't an option so we had to figure it out on our own. When things are fantastic, I make it a point to remember how it feels so I can recall the feeling during difficult times. We both have the same twisted sense of humor, so we laugh a lot. I can't tell you how valuable that is.