Editor's note: David Weinberger is a senior researcher at Harvard University's Berkman Center for Internet & Society and author of "Too Big to Know" (Basic Books).
(CNN) -- As April 15 approaches, the fact that we tell time in circles brings us to remember the attack on the Boston Marathon one year ago.
But what exactly is there to remember? Beyond the facts, what's worth keeping so close that it becomes a part of ourselves? That matters. Every memory changes us, so what we choose to remember depends on -- and reveals -- what sort of people we want to be.
Of course, the memories of the three people who were killed that day certainly will stay forever in the hearts of those who knew and loved them. The pain of the survivors will not be forgotten quickly.
But for those of us who do not know any of the victims, what does it mean to remember their pain and the suffering of their loved ones? That terrible things happen? That sometimes those terrible things are caused on purpose? We'll be reminded of those facts by the heightened security at the 2014 Boston Marathon. It would be foolish to forget that the marathon is an inviting target.
But focusing solely on the pain and loss of the victims doesn't lead us any further. In fact, if taken to an extreme, it can cause us to forget some of our rights and freedoms, just as the memory of 9/11's horrors led us to cede freedoms of movement and privacy to which we had been long accustomed.
So we will learn lessons about security -- perhaps not all of them appropriate. More positively, what should we be remembering and thus letting change us?
For me, one thing to remember is that not a single person who made it to the local medical facilities died. Not one.
In part it was because of the calm determination of those who took care of the injured at the site, moving them to medical facilities where professionals cared for them immediately and through long rehabilitations. It's well worth remembering that in the midst of chaos and danger, the needs of others can drive off our fear.
But from this I also remember the importance of having a medical infrastructure in place, with people and equipment ready to help. The power of training, dedication and an investment in facilities is worth remembering, and then acting on.
I remember how wrong the mainstream media went in its early reportage, and how lost we could become on the Web.
The mainstream media made flat-out errors, and a discussion at Reddit misidentified a killer, causing the falsely accused student's family great pain. We should remember that there are consequences to idle speculation. That should make us more patient and more tentative in our judgments. Knowledge can be hurried but not rushed.
Likewise, I remember being shocked that the younger of the brothers accused in the attack was described so warmly by his school friends as an accepting and empathetic person. From these descriptions, we could learn that no one is to be trusted. I take a different lesson, although one not nearly as neat and clean: People are infinitely complex and never entirely knowable.
I remember the day Boston stayed inside as the killers were hunted. We did this not out of fear -- the chance that they would come down your street with guns blazing was minuscule -- but because it was all we could do to help bring to justice the murderers who attacked our city at a moment of civic celebration.
Boston was strong because Bostonians acted in solidarity. That strength is well worth remembering.
And then there is the memory of the murderers themselves. But I see no reason to remember their names.