She offered to bring fancy cheese, the kind that costs $35 per pound. I said a couple of supermarket slabs would be fine, for one-fourth the price.

Four days later, she dumped me.

Was it the cheese? Did the cheese represent something bigger? Or was the cheese just an innocent bystander? I had been through too many breakups to let it go. I had to parse the cheese.

She and I had been dating for four months. Had the cheese been for our own consumption, I would have gladly welcomed hers. No denying: She had much better cheese. But the cheese wasn’t primarily for us. My two children were coming for dinner. They’re 20-something grown-ups, but not so grown-up that they’re cheese snobs. And I thought it was my paternal duty to keep it that way.

The temptations of materialism are all around: Become a connoisseur. Demand the best. Assert your authority on arcane matters of quality that have nothing to do with happiness.

My job, as I saw it, was to temper this sense of entitlement. Ordinary cheese would be fine. She had met my children a few times already, so our dinner didn’t carry the weight of first impressions. I also thought she should save her money and splurge on herself. We were both on a budget. Spending $100 on cheese that millennials would inhale like movie popcorn seemed like a waste.

When she texted me a few days ahead of time to say she would be happy to bring a selection of cheeses from her local fromagerie, I texted back: “Thanks! Thoughtful! But I’ll handle the cheese. You don’t need to bring anything.”

Except I didn’t text her back. I wrote the text on my phone, then somehow failed to hit “send.” So on the day my son and daughter were coming over, I drove to pick her up, and she got into the car holding the upscale, rope-handled cheese-monger bag I recognized as a foodie status symbol.

“What are you doing?” I said. “I got cheese. We’re all set.” In fact, my cheese was already unwrapped and sitting on the counter in my kitchen, since even cheap cheese tastes better at room temperature.

She gave me an incredulous look. “What are you talking about?”

“I said I would handle the cheese.”

“No, you didn’t.”

Of course, I didn’t realize in the moment that my text had never been sent. Instead, flustered, I tried to explain about grounding my children (by serving them only supermarket cheese!), which sounded even worse out loud than it did in my head. You can imagine how well that went over.

She climbed out of the car in a huff, and I wondered if I would see her again. But she was just stashing the cheese in her apartment. When she returned, I tried to apologize, but she waved it off. “Cheesegate” had apparently blown over.

I tried to think of a backup use for her gourmet cheese. We would be having dinner with a couple of my friends the following weekend, and her cheese would be perfect for that crowd. It would keep. Maybe even ripen.

Dinner with my son and daughter was fun. My cheese turned out to be perfectly adequate. Cheddar. Havarti. Something with red wine in it. My newish girlfriend seemed to enjoy herself. I thought we were all good.

That was Saturday. The following Tuesday she texted to say she wouldn’t be joining me and my friends the following weekend.

Huh?

We got on the phone.

“Our values are different,” she said, adding that we were not parentally compatible. I hadn’t met her children, and now she didn’t want me to. If I was as cheap with her children as with my own, that would be a deal breaker — even though we were both empty nesters.

She didn’t specifically mention the cheese, but I understood perfectly well what she was talking about. What I didn’t understand was how such a seemingly small thing — a decision about cheese — could come to represent so much more. Couples clash over issues of taste and cost all the time, especially in midlife, when we tend to be so set in our patterns and expectations. How could one clash over cheese be a tipping point from a relationship that was full of enjoyment and possibility to one that was suddenly over?

We texted a bit more, and she seemed frustrated that I was confused. I canceled dinner with the friends I thought would appreciate her cheese, not wanting to go alone. She and I went for a walk instead.

She fielded my questions and gamely tried to elaborate when I failed to understand. Finally, I asked, “Was it about the cheese?”

“Not exactly,” she said. But the cheese highlighted a couple of things that had been on her mind. First, I was withholding.

Because I withheld cheese from my children?

No, because I withheld what could have been a better experience for them.

That word. Withholding. It hit a nerve. I did feel that I had been withholding — not with my children, but with her. Reluctant to show affection. To express myself. That was my baggage from more than a dozen other relationships that had flopped. As an accidental serial dater, I had gotten used to unexpected endings, so I pulled my neck in and tried to limit my exposure. I felt emotions, but it made me feel less vulnerable if I didn’t express them.

But that wasn’t it, she said. We got into a long digression about parenting styles. After my divorce, when my children were still young, I lived for a while with a woman and her son, and parental kinship was so important that it blinded us to other inevitable ruptures.

With my children grown, I thought parental kinship was one compatibility I no longer had to worry about, which would allow me to focus more on all the other confounding chemistries: emotional, intellectual, sexual, romantic, political, financial. But here it was again: Parenting as the priority. I imagined myself dating as a doddering oldster, when incompatible grandparenting styles would be my dating downfall.

There was more. It was important to her to be able to express her generosity every now and then. I had squelched that by rejecting her cheese.

It pained me to think of it that way.

This was a variation on a recurring theme: Control. Everybody wanted it. I wanted it a little more than most, it seemed. I couldn’t argue with her. Doing so would remind me too much of all the other times this had come up in my life and I had insisted it wasn’t true, which would be merely another exercise in control.

But wasn’t the whole breakup based on a misunderstanding? A texting mistake? What if I had hit send on that flubbed text, and she had never bought the fancy cheese?

“It would have happened anyway,” she said. It would have been something else, another incident, no matter how small, that exposed the bigger commonalities we lacked.

And there it was, both the truth and the puzzle. Dating in midlife, when we can be so frustratingly fixed in who we are and how we act, is difficult enough already. We’ve all had our hearts broken, often many times, and we’re afraid to get too deep into a relationship until we feel certain about it. So we seize on incompatibilities, no matter how small, until the growing weight of them tips the whole thing into failure.

People say you’re not supposed to sweat the small stuff — except when the small stuff represents big stuff. But it’s hard to know for sure when small becomes big until you get dumped.

Years earlier, I worked hard to understand why my divorce happened. I kept thinking I was right about everything we fought about, then eventually realized, oh, maybe not. Surely, I had learned a little humility in the years since. But relationships kept ending, and I kept analyzing, and all the analyzing didn’t end the endings.

Why so many flameouts? Were there self-defeating habits I had failed to detect through therapy? Was I making bad choices? Were they making bad choices?

She and I walked for an hour. By the time we finished, I still didn’t understand how Cheesegate had proven to be so consequential, but I knew enough. You can do the work, unpack the demons, seek others who have done the same, and still never convincingly explain why a relationship ends. What you need to do, however, is explain it to yourself in a way you can live with and learn from.

In my case, two lessons were clear: Don’t try to control so much — and raise my cheese game. The kids would probably be all right.

Rick Newman is a writer in Yonkers, N.Y., working a memoir about dating in midlife.

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