4/17/07. When students from Virginia Tech struggled to make sense of the horror that struck their campus last week, they erected a banner on their student center with the date of the massacre. It provided a reminder of a time and a place, a way to express a trauma through white lettering on black canvas. It was an attempt to remember.

Theirs is not the first — nor, unfortunately, will it be the last — commemoration of a tragedy. This desire to remember seems built into us. We sing, sculpt, hold one another, dance, write poems and pray in order to find solace in our most tumultuous moments. Using these forms, we try to incorporate trauma into our lives so that we can give meaning to events that feel meaningless. If we’re going to move forward from the horrors we experience, this process seems essential. Otherwise, evil becomes something like a dangling participle not properly integrated into a sentence. It hangs there, and it has, quite literally, the last word. There’s no hope in a worldview like that.

So through our memorials, we try to find meaning. Perhaps that’s why our nation’s capital is peppered with commemorations of wars and those who represented our country in them. Through carved stone, we remember our history. Likewise, after the Columbine shootings, students draped flowers over Rachel Scott’s car and sat on its hood, sobbing in grief. Leaning against red Acuras, we remember our loves. Or following Hurricane Katrina, memorial services were held in worship spaces across the country. In our religious homes, we remember the possibility of hope.

But if there are right ways to remember, there are certainly wrong ways to remember as well. “Just move on” and “It’s time to get over it” are common phrases in our culture, and they imply that the only way to recover from a traumatic event is to forget it.

The trouble with these cliches is that they conflate remembering with reliving. Reliving traps us in the past, keeps us from existing in the present and building hope for the future. But remembering is different: It is the means by which, again and again, we try to defeat pointless horrors by giving them some perspective. That’s the transformation that must occur if we are to prevent the dangling-participle problem.

This power of memorializing is something I’ve experienced in my own life. I was a junior at Yale on Sept. 11, 2001. I remember that the phone lines were down, and I couldn’t call my family. When the trains were running again, I returned to the New York suburb in which I grew up. I felt isolated and frightened. When the Amtrak drew near Manhattan, the train slowed and passengers huddled near the windows, gazing upon a skyline that had changed forever. It looked tilted — just like my reality — even though rising grey smoke held the place where the towers once stood. Then the conductor asked us to keep a moment of silence, and it became our memorial, our remembrance of a horror that shaped our lives. They were strangers on that train, but they shared something with me — they were mourning, too — and they became my community at a time when I felt profoundly protected. In that memorial, I was offered a sign of hope that I was not alone. I will never forget that, nor should I.

In the aftermath of Sept. 11, I, and so many others, observed endless memorials. Some were noble, some bittersweet and some gut-wrenching: signs for missing people in Grand Central Terminal, military planes that kept watch over Manhattan with their deafening drones, chaplains for the cleanup crews and the putrid stench from the pyre of the Twin Towers. Those memorials challenged and changed our understanding of a horror. The same goes for the students at Virginia Tech. As they wear their school colors and attend candlelight vigils and invite a nation to mourn with them, they bear witness to nightmare. That experience will transform them, in their grieving and their remembering, in their hope and their search to make sense of the insensible. To forget the tragedy would be to forget who they were, who they are and whom they will become. But how they remember is their choice.

9/11/2001. 4/20/1999. 8/23/2005. 4/16/2007. These are the dates that form us. These are the dates that are seared into our memories. These are the dates we cannot — and should not — forget.

Danielle Elizabeth Tumminio is a 2003 graduate of Yale College and a fourth-year student at the Yale Divinity School.