It still hurts to look at. (REUTERS)

The flood of pensive retrospectives is hardly the most pernicious consequence of Sept. 11. But as a daily annoyance, it’s up there with removing your shoes at the airport. And it’s something of a generational pastime. “I can’t come to work this week,” every Millennial says. “I am too busy writing 9/11 retrospectives.” Baby’s First 9/11 Retrospective will be there in the scrapbooks next to those outgrown booties.

But I’m not writing about Sept. 11. I’m writing about Sept. 10.

It’s been 10 years since that, too.

Most of us remember a pre-9/11 world. I am one of the generation for whom the arrival of 9/11 coincided with the end of childhood. I was 13 when the towers fell and that plume of smoke rose silently up from the Pentagon.

It was the first time I wasn’t elated by a day off school.

I remember the screaming and the silence and the same images on every channel.

I remember the day after, the constellations of flags everywhere. I remember the forests of yellow ribbons on cars and backpacks. I remember the endless parade of faces in the papers, the solidarity in the streets.

I remember when we started joking again.

What I am beginning to forget is the time when this was inconceivable.

Everyone remembers 9/11. I want to remember Sept. 10.

“It is true that we live in a post-9/11 world,” a writer in the Harvard Lampoon once quipped. “And things will never be the same. But doubtlessly there is some horrible tragedy yet in our future, and we should savor the fact that we still live in a pre-that tragedy world.”

This summarizes pretty well how we Millennials feel all the time.

Life after the awful awakening of 9/11 reminds me of the beginning of the Tom Stoppard play “Rosencrantz and Guildenstern Are Dead,” where the two title characters sit flipping a coin. It lands heads up 79 times in a row. It’s unnerving.

Maybe there won’t be another large-scale tragedy. But if we aren’t exactly living under the sword of Damocles, we’re certainly watching for Damocles’s other shoe to drop.

I don’t want to reduce us to Generation 9/11. We are not that. Or rather, we are not only that.

It would be as false to say that we are always thinking about it, as to say that we’ve forgotten it entirely. We are what we are both because and in spite of 9/11. It’s what gives us the impulse to write all these retrospectives.

That day instilled in us our characteristic attitude of optimistic fatalism. Once the inconceivable happened, it ceased to be inconceivable. After it happened we had to reconcile ourselves to the thought that it might happen again. We are hopeful for “if” but reconciled to “when.” Somewhere at the back of our minds, we are holding our breath.

Of course we have to forget that we are. That is the whole trick. Fortunately we now have things like irony, the iPhone and Lady Gaga.Handy. Distracting.

I read once that the feeling of your shoes against your feet is a sensation that the brain generally chooses to ignore. There are other more important things to think about, and you can’t go through your life every day fixated on your shoes.

That’s life post-9/11: ignoring the rub of the shoe. Every so often you notice — say, removing them at airports. But you cannot live properly holding your breath.

So we forget.

The neighborhood is no longer quite safe. There is a snake somewhere in the garden.

We sit here tossing our coins. Heads. Heads. Heads.

Sept. 11 was an awakening of sorts for everyone, just like the assassination of JFK or, before that, Pearl Harbor. It brought the realization that there was no safe, only safer.

But for us it was more than that.

Innocence I would loosely define as the lack of awareness that you are pre-anything. It’s the garden stay of indefinite duration.

I don’t know how much of it was Sept. 10 and how much of it was simply childhood. I remember, though, not cowering below a desk at the sound of too-loud thunder. I remember, vaguely, keeping my shoes on at the airport. I remember not being able to find Afghanistan on a map.

There is always some consolation. With the end of innocence comes wisdom, a sense of perspective, whatever the going word is. In the wake of tragedy came solidarity. Everyone was so friendly and proud to be American and we approved so much of the job the president was doing and yellow ribbons blossomed on all our old oak trees and cars. And life went on.

It had to. We can’t spend our whole lives thinking about it. That is why Rudy Giuliani exists. I hear that every time someone writes a retrospective, Giuliani gets another pair of wings.

But I miss Sept. 10. I miss not waiting for the shoe to drop. I miss not knowing that there was a shoe.