On September 11, 2011, I stood in front of the American flag and wept for the people who perished on that black day. I also wept in shame. Ten years have passed since the attacks, and yet I can still never forget what I felt the day those planes hit the towers: nothing.

Like all Americans, I remember exactly where I was when I learned we were under attack. I was sitting in my fourth grade class when I discovered that my father had come to take me home from school early.

"Two planes have just flown into the World Trade Center towers," he told me, and I nodded at him and pulled a concerned look.

Unlike some Americans, who describe the rest of the day passing in almost a surreal fog, I can clearly recall what I did when I went home. I played with toys. I watched TV. I did my homework. And I had a thought that haunts me to this day: "Sweet! A day off from school."

The adults all understood what had happened; for them, it wasn't sugarcoated. They watched as people leaped from the towers to their deaths; they feared for the rescue workers who rushed into the buildings; they felt their hopes crumble with the towers. They feared for their loved ones and cried as bodies were removed from the rubble.

It was a day that changed lives; the adults never even considered that the towers could fall. The disappearance of the two buildings was almost inconceivable, as were the deaths of the thousands who worked inside.

And to me, it barely made a difference. All I knew was something incredibly tragic had happened. But why did it matter to me? I lived halfway across the country, so how could I tell the difference between that one day and the next?

A decade changes a lot. On Sunday, I watched the flag wave at halfmast as I tried to keep my composure. I almost couldn't remember a pre-9/11 world; for me, nothing had changed. Life had gone on, the Earth kept spinning. I couldn't describe a single difference between the two worlds. Yes, I could tell you what I have been told is different, but not what I have seen.

As I stood under the sun, I remembered that my brother had a friend who lost his father in the attack. It was incredibly important that I remember who the father was, or even who the friend was, but I could not. I couldn't even remember their faces. All that was left of them in my mind were statistics, just numbers that eventually became associated with 9/11. I couldn't handle it, and broke down and sobbed.

A friend consoled me as I cried in front of the flag.

"You were only a child," she told me. "How could you know what it meant?"That's the point. How can we "never forget" if we never knew in the first place? How can my generation hope to understand what occurred? We were only children—we didn't have the maturity to understand.

And what happens when we are gone? The generation that succeeds us will understand even less, until finally, 9/11 becomes a day we recognize in a history book. The last attack on Americans was at Pearl Harbor, more than half a century ago. How many Americans can even remember what day it fell on?

So I wept as the flag flew straight in the breeze. I did not cry merely for the death of the thousands of my fellow countrymen; I cried for the coming death of their memory.

Adam Eichenwald is a member of the Class of 2014.