It has been almost two decades since I stared up at a shard of the World Trade Center’s exterior that had somehow survived the implosion of everything around it. Twisted and scarred but still upright, it towered above me by several stories.

The date was Sept. 17, 2001. The rubble was still smoking. As silly as this sounds, I was hoping it would make me cry.

It was six days after the attack, and I still hadn’t cried, even though people I knew were missing and presumed dead. I’d thought I was numb because I was watching it all through the filter of my television. But now I had taken a temporary administrative job with one of the construction companies that was digging into the rubble, hoping for survivors, expecting to find bodies. I thought that when I confronted the devastation in person, I’d be able to properly mourn.

That didn’t happen. The truth is, it still looked like something on television, a surreal shot from a disaster movie. I was stunned but unmoved.

The tears came two weeks later, when I walked out of the subway and came face to face with a wall of fliers posted by people looking for missing relatives. They showed pictures of happy moments — birthdays, graduations, engagements. Many had those tabs cut into the bottom with phone numbers you could tear off, perhaps a dozen per page. But the fliers still had all their tabs.

I dropped to the pavement and sobbed so hard I couldn’t see, or move, for some 10 minutes. No one disturbed me. In that time and place, I’m sure it didn’t even seem particularly weird.

Later, trying to understand the difference between those two moments, I told people, “The rubble still didn’t feel real.” But now, after a year of pandemic, I realize that wasn’t the problem. The rubble was real, all right. It just wasn’t normal. With no framework into which the devastation fit, my brain reverted to its closest analogue: a picture on a screen.

I’ve thought a lot about those two episodes over the past year, while witnessing the occasional human triumphs and frequent human failures of a once-in-a-century global pandemic. Every time I asked myself what was going wrong, it always, somehow, came back to that essential human craving for things to be normal, and our inability to believe that they are not, even when presented with compelling evidence.

This phenomenon is well-known to cognitive scientists, who have dubbed it “normalcy bias.” From movies, you’d think that when disaster strikes, people trample each other in their panic. But the greater risk is more often the opposite: People can’t quite believe. They ignore the fire alarm, defy the order to evacuate ahead of the hurricane, or pause to grab their luggage when exiting the crashed plane. Too often, they die.

One of 9/11’s most haunting details involves the South Tower, which was struck 17 minutes after the first. It seems likely that if people had started urgently evacuating right after the first plane hit, many of the 600 who died might have lived. But the standard evacuation plans called for emptying affected floors, not the entire 110-story building, and if a plane crashing into the North Tower wasn’t a normal kind of disaster, who could say how different it really was?

So the building’s director did the normal thing, waiting for the fire department or some other authority to order a broader evacuation.

This no longer seems that odd to me. In March, just days before much of the country shut down, I told the folks at my dad’s cardiac rehab facility that we’d be coming up to get him in a few weeks. “Don’t worry,” I said. “I’m isolating!” In the pained silence that followed, I realized they thought I was some hysterical germaphobe.

With every awkward moment like that, I wondered why I was trusting my own amateur analysis over that of professionals who didn’t seem all that worried. I bought extra food and toilet paper; I doused myself in hand sanitizer after every event I covered. Eventually, I wrote a column explaining why I expected disaster, even though everything still seemed fine. But in between, I doubted.

Calling the quest for normalcy a bias makes it sound bad, but most of the time this tendency is a good thing. The world is full of aberrations, most of them meaningless. If we aimed for maximal reaction to every anomaly we encountered, we’d break down from sheer nervous exhaustion.

But when things go disastrously wrong, our optimal response is at war with the part of our brain that insists things are fine. We try to reoccupy the old normal even if it’s become radioactive and salted with mines. We still resist the new normal — even when it’s staring us in the face.

Nine months into our current disaster, I now see that our bitter divides over pandemic response were most fundamentally a contest between two ideas of what it meant to get “back to normal.”

One group wanted to feel as safe as they had before a virus invaded our shores; the other wanted to feel as unfettered. The disputes that followed weren’t just a fight to determine whose idea of normal would prevail. They were a battle against an unthinkable reality, which was that neither kind of normalcy was fully possible anymore.

I suspect we all might have been less willing to make war on our opponents if only we’d believed that we were fighting people not very different from how we were — exhausted by the whole thing and frantic to feel like themselves again. I even suspect that with more mutual empathy, we might have reached a detente, rather than making the pandemic yet another proxy for the same old culture wars. Though, of course, that itself was one way of feeling normal for a bit.

It’s too late now to correct those errors, so we’ll just have to wait for our new normal to arrive. After a decent interval, we might have the time and perspective to sort out who was right and who was wrong, so we all can try to do better next time. Though I’m sure we’ll never agree on the whole truth of the pandemic, since no one person will ever know what that was.

For months, I kept walking around and around Ground Zero, long after it started looking like a normal construction site. I circled, and I stared hard at what was missing. I was still trying to have that movie moment when I would take in the enormity of what had happened, and turn thereby toward some kind of resolution. My moment never came.

Some catastrophes are simply too big to be understood except in the smallest way, through their most ordinary human details: a smiling young woman flashing an engagement ring for a camera, and a row of untouched tabs beneath that picture, bearing a phone number that no one ever called.

America has a million such details to choose from in 2020, but for me the most telling will be the one I still cannot quite comprehend: the Zoom weddings and FaceTime funerals. How determined we were, how desperately we tried to make those images on our screens as real and profound as all the normal human moments we could no longer have.