When Alejandro and I met in New York 10 years ago, we fell in love quickly. But we knew we could never end up together. 'We're from two different worlds,' we would say.

I laugh when I think about that now. A marriage, 4- and 5-year-old sons, and a cross-country move to Los Angeles later, that vast gap we once saw as an implacable barrier to our relationship is a foggy memory. The fact that he is from Uruguay and I am American no longer seems like a big deal: He became a U.S. citizen two years ago, and my Spanish is now good enough that people sometimes mistake me for a South American. He's Jewish and I'm Catholic, but we agreed early on that we'll raise our kids Jewish as long as we can have a Christmas tree.

Far more troubling than either of those divisions was the fact that I grew up in the privilegedbubble of the American upper middle class, while Alejandro came from a family that struggled to cling to the lower rungs of the middle class in Latin America, and eventually fell off them. When I met him, he was working as a moving man in the South Bronx, a job he did for nearly a decade, to support himself and his parents back home. What he called my 'princess' traits horrified him, while the harsh reality of his life scared me. Today, I am so proud that my husband, who owns his own trucking company, is a true self-made man.

Alejandro isn't particularly philosophical, but I see much wisdom in a refrain of his: 'Every person is a complete world.' We may be more dramatically different from each other than many couples, but our union illustrates the drama of any marriage: It's always a merging of two distinct worlds. And no matter how seamlessly and harmoniously blended those two worlds become, there are always reminders that once upon a time, you were like two distant planets, spinning on their own axes.

And that's what this column will focus on-how two people can unite to make all the choices, plans and decisions marriage requires, even when they come from two different worlds.

Alejandro and I overcame so many differences to be together that I think we've grown smug over how compatible we are. We have rarely argued about money.

But lately, we've been working our way through a list of important financial decisions, including possibly buying a house, writing a will and forming a trust. These conversations have cured us of any smugness about how perfectly our worlds have merged. Funny how much harder it is to agree on financial issues when you actually discuss them.

When I came to him recently, agitated and shaky, because I had discovered an enormous shortfall in our retirement savings, he stunned me by basically not caring.

'I'm not worried about it,' he said.

How could that be, I asked? His own father is living through the nightmare of a penniless old age. I ran through the numbers for him, trying to inspire at least some mild panic. No reaction.

Our financial planner told me we both would have to put more of our earnings into tax-deferred accounts. The extra contributions would take a big bite out of our monthly budget, and we both needed to be fully committed in order to make it happen.

In the midst of this, Alejandro mentioned conversations he was having with a couple of architects about buying some investment properties with them.

When Alejandro brought up his property scheme just as I was trying to figure out how to patch our retirement shortfall, I could barelycontain myself.

'I don't understand this. What are you envisioning for retirement? What could possibly be in your head?' I said the words with anger, imagining only the lamest answers. But, in one of the rare gifts a failure to communicate can give, he didn't pick up on my facetious intent.

Instead, for the first time, we had a long talk about the retirement mentality in the world he's from. Everyone he knows, he said, dreams of retiring with some income properties-it's widely considered a surefire investment. He strained to think of anyone he knows who actually pays the income tax they owe, which helped explain why tax-favored funds don't have the same totemic power for him that they do for me. Most significant, after a childhood marked by horrific hyperinflation and dramaticcurrency devaluations, it made Alejandro queasy even to contemplate locking money into funds that he wouldn't be able to tap for decades. That's why he wasn't worried about having enough money in an IRA: To the contrary, it made him feel safer not to have it there.

We talked about how we couldn't allow fear instilled by the world where he'd grown up to determine how we would approach retirement savings here. So we started drawing up a plan-one that indeed involves a lot of painful locking up of today's money for tomorrow. That leaves a smaller amount of money available for a lease property, but, understanding that it would be part of a diversified retirement plan and because Alejandro is game to do the work it involves, I'm game for exploring a modest investment.

If all goes well, someday we'll retire with a place in the U.S. and a place in Uruguay. And then we really will live together in two different worlds.