We married at 26. Stood on the deck of this tiny boat, off the coast of Alaska and exchanged vows with a Hershey's bar broken in half so the split made "hers" and "heys." No rings. I wore a white fisherman's sweater inside out to hide the dirt. Sam wore black fleece pants, a purple sweater, and a knit cap. We were half drunk and laughing all the way through.

Three years later we bought $1.50 wedding bands in a Mexican silver-mining town where white houses with terra cotta roofs stacked up and down the mountainside.  

Some people enter marriage with picket-fence visions and expectations about mortgage loans, career paths and who will do the cooking. I had a great friend, lover and travel partner, and that was all I wanted or needed or expected back then. That was my expectation. I never considered what I'd require from a grown-up, settled down partner. We snickered at career-path jobs, and rented houses without considering buying a home because who wanted to be tied to a mortgage working 50-weeks a year to pay for it?

It all worked perfectly, until it didn't.

Because after Alaska, Mexico and traveling off to somewhere new every time life got hard, I was 30. I wanted us to settle down, have kids, get jobs with possibility and live in a house for longer than three years.

I thought, of course, Sam would shift right with me. When our first daughter was born, I expected it to go without saying his top priority would be our family's stability.

He expected to quit jobs when he stopped liking them. He spent a year trying to build his own design business. When he discovered he hated the business end of it and how having to constantly generate work really sucked, he expected to drop the business and finish his degree by taking full-time classes and working the kind of campus job I'd had at 19—when my parents bankrolled my life.

He expected life as a daddy to be exactly like before, but with a kid. Every time he switched directions, I rearranged my life to accommodate. And I said nothing. By the time our second girl was born he'd burned through three jobs in as many years.

I wanted him to suck it up, keep a real job with a real income, do night classes—the way other grown ups with children finish school. And when I finally found the voice to tell him, that's when we started coming apart.

Every marriage, failed or not, has its list of "she dids" and "he didn'ts." I think there's a reason some can outlast pressure and pain that would crush other relationships three times over. Both partners have to know the difference between disappointments and deal breakers, define the absolutes, communicate expectations and—the hardest part—learn to let go of everything else. Which is most of what we struggle over: everything else.

The things that killed my marriage the first time were deal breakers, but they grew in the vacant space where our communication should have been.

My friend Jane and I scrutinize the "why?"s and "what's acceptable?"s and the "how do you get there?"s in marriage. She's been married 17 years and dated her husband for six before that. At 45, that's half her life.