Twenty-three years ago, as the nation approached September 11—a date unlike any other in the American mind—no one could have imagined the horrors that would soon befall the nation.

Back then, it was unimaginable that crazed Islamic extremists could hijack a single airliner, let alone four. And that they could fly those planes into pedestrian malls and government buildings was unimaginable.

It was unbelievable that nearly 3,000 Americans could soon become victims of a brutal terrorist attack.

But that was life before September 11th – a life that was about to change forever.

On that fateful morning, singer Harry Connick Jr. was celebrating his 34th birthday. A promotional poster and trailer for Sam Raimi’s upcoming Spider-Man film featured the Twin Towers prominently (both were soon edited out of respect). The president had, as Dan Bartlett, deputy White House communications director, put it, “pretty run-of-the-mill” day ahead. From what one hears, the nation had a “pretty run-of-the-mill” day ahead of him.

But nothing could have been further from the truth.

“The lasting impact of the September 11 attacks is clear,” Pew Research Reports“An overwhelming number of Americans old enough to remember the day still remember where they were and what they were doing when they heard the news.”

The news.

The news that American Airlines Flights 11 and 175 had flown into the World Trade Center and that American Airlines Flight 77 had hit the Pentagon. The news that New York City’s tallest towers had collapsed. That a fourth flight, United Airlines Flight 93, was en route to the nation’s capital.

The news that America was under attack.

According to Pew’s first survey, conducted just days after the attacks, a majority of American adults (71%) said they felt depressed after the unforgettable events of that day, nearly half (49%) had difficulty concentrating, and a third said they had trouble sleeping. “The following August,” Pew added, “half of American adults said the country had changed ‘in a big way’ – a figure that actually increasedto 61%, 10 years after the event.”

What began as an ordinary day evidently ended up being the most haunting in recent American history. To this day, most Americans cannot comprehend the evils committed on that day.

But there was something else that was and remains incomprehensible about September 11: the national unity that followed.

For a brief but poignant moment in American history, policy no longer mattered. Our divisions and disputes became insignificant. What mattered was that we all We are Americans – one nation under God – and we were under attack. In the face of unfathomable tragedy and unspeakable evil, we would band together, stand together, and support one another.

We were united.

Today, when we say “never forget” – a solemn promise made after 9/11 – we vow to do more than just remember the tragic events that shocked our nation. We also honor the unity, faith and patriotism that have strengthened us and rekindled our love for the red, white and blue. It reminds us that despite the darkest tragedies and trials, America has always prevailed, and that if we can only stand once again alongside God and our fellow man, we can continue to triumph over adversity.