My oldest child, Matthew, was not quite two years old on 9/11. He has no memory of the event, though it happened before our very eyes, including his. We were living in Brooklyn then, at the waterfront, with a clear view of New York harbor. We did not see either plane hit, but were inside our apartment when the second plane struck the south tower. We heard people on the street screaming just before the impact, heard the horrible sound, and felt our building shake from the concussion. I was a columnist for the New York Post then, and ran on foot out of the apartment and across the Brooklyn Bridge, hoping to get into lower Manhattan to cover the story. I stopped several times on the bridge to interview dazed people, some of them bloody, staggering out of the Wall Street district and across the bridge to safety.

It never once occurred to me that either tower would fall down. In fact, I ran into one of my Post colleagues, a reporter who wasn’t due to come to work till that afternoon, out riding her bike. We stood on the bridge together trying to make sense of what was happening. I told her I was going to get as close as I could.

“Don’t,” she said. “Those things are coming down.”

I looked at her like she had lost her mind, and told her no, that wasn’t going to happen.

Less than a minute later, the south tower fell. The sound was like a roaring waterfall. I ended up going back to Brooklyn. Julie, with baby Matthew in her arms, shrieked when I walked in, with a light coating of dust on me. She had not been able to reach me on my mobile phone (cell service collapsed when the north tower did), and did not know if I was alive or dead.

Driving to New Orleans on Friday for the concert, Matt, now approaching 17, asked me what life was like before 9/11. I had never thought about that. It was kind of like asking what life was like before the Internet. The Internet has become so much a part of daily life that it’s hard to recall when it wasn’t here.

I told Matt that I think the biggest change is that the country is far more anxious now than it was before. We had just come off the 1990s, a decade in which the Cold War ended, the economy was booming, and America stood astride the world as the lone hyperpower. That all ended on 9/11. The shock of the event is hard to convey to a young man who has grown up knowing war and global terrorism as part of his daily life (though thank God, not as a local phenomenon, at least not for him). I remember that fall of 2001, sitting at a sidewalk cafe in Manhattan with a friend, both of us talking soberly about what we would do with our families if terrorists set off a dirty bomb in Midtown. We were dead serious, and it was by no means a crazy conversation to have in those days. Once you’ve seen the unthinkable, you know that anything can happen.

I don’t have those thoughts anymore, and haven’t for a long time. But you never quite feel secure in the world after you’ve lived through something like that, at least not if you saw it up close (“it” being not only the event, but the aftermath; I remember the burning sensation in my nasal cavity that lasted for weeks, and was caused by something in the smoke from the pile at Ground Zero). Anyway, I told Matt that 9/11 showed us that we were not invulnerable after all. Then the Iraq War showed us that we were not a hyperpower capable of ordering the world according to our will. These were hard lessons to learn as Americans. And then, in 2008, came the economic crash, which revealed how unstable our economy was.

That terrible day inaugurated an era of great anxiety from which we have not yet emerged. I was thinking this morning about how strained the social fabric of America seems to be today, and thought back not to 9/11/01, but a year later. On that date, I walked from Brooklyn with a friend to the one-year memorial service at Ground Zero. Only dignitaries and family members of the dead were allowed onto the site; the rest of us gathered outside, along the perimeter of the hole, which was surrounded by fences. Eerily, at on or very close to 8:45 a.m., a year to the moment from when the first plane hit the Twin Towers complex, a strong, steady 45-mph wind appeared, blowing from the same direction as that plane. I remember the direction, because I observed before the wind started that had I been standing on that very spot a year ago, the plane would have entered the north tower directly above my head.

The wind seemingly came out of nowhere, and it started just as the ceremony began at Ground Zero. It’s the kind of wind that you associate with a storm front moving in. But there was no storm. The skies were clear. It blew with a freakish ferocity, all throughout the Ground Zero event, in which people present read aloud the names of all the dead. I had become separated somehow from my friend, and ended up a couple of hours later inside Trinity church on Wall Street, where the Archbishop of Canterbury led a memorial prayer service. The wind was still howling outside when I went into the church, just as it had been constantly since just before 9 that morning. At some point during the service, we heard the bells ring outside the church, at Ground Zero, signaling the end of the names ceremony. It wasn’t long before the Anglican service ended too. When I exited the church, the winds had stopped. I can’t say for sure that the gale ended as soon as the last name was read, bringing the Ground Zero ritual to a close, but it definitely ended after the Trinity service began.

Like I said, it was eerie.

Later that day, back home in Brooklyn, I received an e-mail from my friend, who lived at that time in my neighborhood. When she got home from Ground Zero, she noticed that a small antique American flag she had framed under glass and hanging on the wall of her office had torn in two, right down the middle. She found it unnerving, and invited me over to see it. She swore that it had never been like that, and to the best of her reckoning, had somehow come apart that morning, during the ceremony.

Understand: this antique American flag was inside her apartment, framed under glass, and hanging on her wall. Something tore it. True, it might have come apart earlier, and my friend only noticed it that day, but I don’t think so. She looked at that flag every single day. On this day, September 11, 2002, it was torn.

It unsettled us both, because it seemed so blatantly ominous. Over time, I forgot about it. This morning, on 9/11/16, it came to mind again. I think it was actually an omen, but even if it is just an accidental symbol, I think it reveals a lot about how America is different today than it was before September 11, 2001.

Anyway, I put the question to you: How is America different today than it was before 9/11?