My husband and I married in 1985. Ronald Reagan was president, Intel introduced a 32-bit microcomputer chip that year, and Amadeus won the Oscar for “Best Picture.”

Thirty years later, “we are still married,” to borrow the title of one of Garrison Keillor’s books. Our lives are intertwined physically and financially. We are parents and partners and, on the good days, good friends.

We are family, and — like a growing proportion of college-educated couples in which women are financial and decision-making equals — we have chosen, despite the odds, to remain married.

I don’t believe in divorce once children are part of the equation. And so, as a belated anniversary gift to David, and a reminder to those bored and frustrated marrieds who see uncoupling as inevitable or an easy out, I’ve articulated three reasons why.

Cherish your history

We met in a Shakespeare class at the University of Minnesota taught by the gifted Toni McNaron, then a newly sober and recently “out” tenured professor who challenged us to see the Bard through a contemporary lens.

David loves to tell the story of eyeing me from across the room but thinking I was too young to date. I remember being drawn to him in a way that was inexplicable till our first son, Sam, was born in July 1990.

Together, we have invested in property, made homes, made friends, made joint decisions on causes and organizations to support. We both come from small-town, middle-class families with professionally employed, well-known fathers. Born into privilege, we take pride in living frugally.

David and I sometimes muse that we were brought together for the divine purpose of creating our sons. Every mother may believe that. I know it to be true. Sam and Nate are strong, intellectually curious and kind-hearted young men — and our greatest achievement has been raising them well.

Yes, we’ve stayed together for the kids. That is the legacy and lesson of my parents’ divorce, which they announced the day I turned 14.

“Parenting has been a tough haul, but we’ve worked hard at being a team and have started to reconnect on date nights,” says a neighbor, 52, who has been married 20 years. “We both come from divorced families, and that has left a lasting impression on both of us, so we are cognizant of the reason we are together — not just for each other, but for our whole family unit.”

Work through anger

I remember the door-slamming, plate-throwing fights of our younger, more passionate years with detached amusement. Who has time for that now?

In our 30 years together David and I have buried (or scattered) one parent, three siblings, two dogs and even some friends. Time speeds up with each passing decade. Experience has shown me how little we control what twists and turns our lives will take, or how our sense of security may be uprooted.

A boss once told me she feared losing her “edge” as she got into her 50s. Not so for me. I like the softness and compassion that have come with age.

Invariably, when either David or I gets moody or short-tempered, we shift gears, forgive quickly and move on. We don’t have time for sharp words or prolonged resentments, the drama that once fueled what we took for romance.

Laughter and companionship are key in long-term marriage. “We talk, always,” says a friend who has been married 15 years. “We’re honest. We laugh a lot. We take care of each other, not because we have to — but because we want to.”

Love the one you’re with

Stephen Stills’ paean to infidelity has a different meaning to me after three decades of marriage.

David and I are under no illusions that we were “made for each other.” In fact, our temperaments and interests often diverge. His relaxed approach to agendas and timelines drives me crazy. My quick-paced brainstorming and tendency to think aloud set him on edge. He smokes and loves sugar. I eat consciously and exercise daily.

Each of us has friends of the opposite sex and could be happy with someone else — or contented on our own. We’re both readers and contemplative types at heart. But we found each other, and that’s the clay we shape and mold.

Our differences coalesced into a surprisingly congruous approach to raising our sons. Aside from religion — I don’t think we exposed them to enough of it; David went on too many forced marches to Mass ever to inflict mandatory church-going on his kids — we have few disagreements about values in our household.

Growing up together helps. “John and I have a long history together,” says a friend and former coworker who has been married for 23 years. “We met at age 18 and got married at 24. Our life histories are intertwined.”

When I told my husband I was writing a blog post on how long-term marriages endure, he objected. “You didn’t ask me!” he cried.

So, what’s kept us together? His response touched and surprised me, even after 30 years: “Love.”