Americans today tend to have a short attention span. Important news often is quickly overshadowed by the latest nonsense posing as news that captures the nation’s attention.

Yet some events are of such a magnitude that they remain seared in our memories. The attack at Pearl Harbor. Troops storming the beaches at Normandy. The fall of Saigon. And the events of Sept. 11, 2001.

For those old enough to understand what was happening 24 years ago, when terrorists hijacked four planes — two of them brought down the World Trade Center, one smashed into the Pentagon and the fourth crashed into a field in Shanksville, Pennsylvania — those events will forever be imprinted in our minds.

But for many younger people, 9/11 is, at best, a vague recollection of events that seemed to shock adults around them to the core. For even younger Americans, the attack on our nation is mere history.

Those youngsters never knew a world in which the Twin Towers defined the New York City skyline — or one in which the United States did not have troops serving overseas.

Most of them also are too young to remember how Americans came together to “Never forget.” They don’t know the horror of learning nearly 3,000 people were killed because violent extremists used their religion and political ideology to justify an attack on freedom. They don’t know what it felt like to watch a nation come together and declare that what we stood for was worth protecting — worth fighting for; and that we made that declaration as one people. We had each other’s back. We supported our troops protecting our freedom.

So today, as we look two-plus decades into the past to one of the most terrifying moments in American history, we must, indeed, never forget. We must never forget what it is about this nation that so infuriated those who sought to destroy us. We must never forget those who died — nearly 3,000 lives whose absence must spur us to be better, to remain a beacon of freedom for the world. And we must never forget the nearly 4,600 U.S. servicemembers killed in the Iraq war and 2,500 killed in Afghanistan. Their loss must inspire us to ensure they did not die in vain.

At a time when it feels as if politics is driving a wedge between Americans, we must commit to coming together to stand up for the land of freedom and opportunity. We must lift one another up instead of tearing each other down. We must always remember we are, still, the United States of America. And today we are united once again by the vow that while we may be different, we are indivisible, that we are one nation, under God. That, we must never forget.