It has been 17 years since the world forever changed. For most of us, it’s hard to imagine a world without the terrorist attacks of Sept. 11.

But for many, it’s an event relegated to history books. They were born in the days, months and years since, and have grown up undoubtedly shaped by the event but never fully aware of how much that day changed our great nation.

They didn’t watch two airplanes claim the lives of thousands as they struck the Towers. They didn’t watch those same Towers crumble to the ground, burying first responders. They didn’t experience the fear and panic that struck at the heart of America.

They didn’t witness monumental acts of courage and sacrifice. They didn’t watch a great country respond with greatness.

They can read the stories, look at photographs and watch the many hours of archived television footage. But it’s not the same.

There is danger in relegating events like 9/11 to history. Lost lives becomes numbers on a page. Crumbling towers become graphic photos. Stories of the sacrifices of many are simply lost.

That’s why it’s imperative that those of us who saw, who experienced, who witnessed that horrible day share it with future generations. They should know just how significant that day was — we’ve fought two wars and lost thousands more lives because of it.

The world we live in now continues to be shaped by Sept. 11 and the response to it. It’s important that future generations understand the day’s impact. But they won’t understand unless we tell them.

If we do nothing else to mark the event this week, we should explain to our children and grandchildren the magnitude of that tragic event. Not to scare them or pass our fears on to them, but to give them a better understanding of our recent history and our immediate future.

This editorial was first published in 2015.