Sitting in a bar across the street from Ground Zero in early 2012, listening to the 24-hour construction sounds, I tried to remember that September morning when we held our breath.

It has been over a decade since the Twin Towers fell. Like many people, I’d watched the scene unfold on television. The images have receded somewhat, no longer played over and over in our minds. Humans are capable of forgetting a great deal.

I saw the new towers, construction fences surrounding the site, and New York’s finest, dressed in starched blue shirts, standing guard. I took some comfort in the structures emerging from the scarred earth, resting on ground that holds the weight of enormous grief and loss.

Earlier that day, we’d visited the 9/11 Memorial. It is a fitting tribute: A pair of seemingly bottomless pools, located on the footprints of the original Towers, with waterfalls cascading in a never-ending cycle. You can touch the names of the dead, trace the lines and curves with your finger. Was this one a father? Someone’s spouse?

I stood there and cried.

Meanwhile, people took photos of their families and friends. They posed for selfies. They smiled in the face of all those names.

Later, I talked to David, a young security guard, at the Memorial. He used to deliver newspapers to the top floor of one of the Towers. He wasn’t there that morning. “This is the best place and the saddest place I’ve worked,” he said. He smiled and shook his head. “People treat this place like it’s Disneyland.”

I think I understand why we trivialize strong emotions. It hurts to remember; it is easier to forget. I read somewhere that the act of remembering is a tribute. It is not as concrete as a memorial, or as obvious as a photo. It doesn’t always require tears. It does require reflection.

Some events are worth remembering forever; this is one of them.