As you sat across the Thanksgiving table basking in the warmth of family and the aroma of chestnut stuffing, most likely you did not remember the vicious comment your Aunt Jennifer made about you a few years back. You didn’t dwell on Uncle Julio’s unkind reference to your drinking last Christmas or what cousin Duwan said about your girlfriend during that dreadful vacation at the shore. At family holidays, we tend to embrace our relatives even after months or years of not having seen one another, regardless of the quarrels we have had in the past.

We may chalk up our generous forgiveness to the festive spirit of the holiday, but the real reason has nothing to do with Thanksgiving; it is because of how we humans remember — and forget. Cognitive experts tell us that forgetting is fundamental to how we make sense of the world. Forgetting helps us survive, by making sure we don’t dwell in the past.

In the digital age, that mechanism of our humanity is under threat.

We all hate when we can’t remember something. We think of it as a bug of the human mind. We don’t realize that by discarding most of the avalanche of details that our senses are bombarded with every day, as well as past wounds, our brain helps us focus on the important things; it lets us see the forest rather than just the trees. We may learn from our failures, but thankfully we also easily forget them.

Human memories are not fixed, they are reconstructed. We remember more easily what we remember often. More important, we tend to forget memories that don’t fit into our current world vision; our brains discard them as no longer important. That way, we forgive one another (and ourselves) for past transgressions. Thus our memories of most past experiences wither. Of course, that process takes years, as more and more details dwindle in our minds.

Forgetting misdeeds that we deem no longer relevant is a powerful mechanism; and the best part of it is that it’s built into us. We don’t have to do anything consciously to make it happen. But it also means that operation is thwarted in a world of comprehensive memory, a world in which we are constantly reminded of our past.

Our ever-improving digital tools record billions of Facebook messages and more than 300,000,000 tweets every day — not to mention our private e-mail accounts, with their photos and videos. Logging our lives is becoming the norm, and having a comprehensive digital memory at our disposal is the default.

Many people are concerned about what this does to privacy. I am worried about Thanksgiving — the warmth and joy that may be lost when we keep being reminded of every mistake, every quarrel, every disagreement.

Consider the following scenario: Some years back, Jane was accused by her cousin John of neglecting a sick family member whom she was on her way to visit. The accusation wasn’t entirely fair; Jane had gotten caught in traffic and thus her ill aunt was alone for an hour. Not believing Jane’s explanation, John sent her a nasty e-mail saying she did not care enough for the family. The e-mail infuriated Jane, but as time passed the memory of the incident faded and more recent and pleasant memories replaced the bad one. But suppose, while searching for driving directions to this year’s family gathering, Jane stumbles over John’s e-mail just as she is about to see him. With her anger revived by rereading the old message, will she be able to face him without the recalled memory biasing her judgment?

With comprehensive digital memories all around us, forgetting one another’s offenses becomes more difficult; through our digital tools we’ll be alerted to all that we thought we had forgotten. This will make it harder for us to forgive.

In one of his short stories, the Argentine author Jorge Luis Borges describes a young man who after an accident can no longer forget. He can remember perfectly all the books he has read, but he has been unable to learn anything from them, because learning involves the distilling of abstract thought from detailed memories, after which the latter fade away. Thus it, too, necessitates forgetting. In future Thanksgivings, our data glasses might identify family members through facial recognition, and within a split second, display old e-mails and images, tweets and posts, reminding us in excruciating detail of their (and our) past shortcomings.

Some say that we’ll adapt by disregarding these digital memories. But it is naive to think that if so directly reminded of earlier quarrels, we’ll be able to put the revived memory aside. Our brain is trained to remember events we thought we had forgotten when given an external stimulus. Automatically disregarding revived memories is as hard as deliberately forgetting things — we can’t do it.

We need to appreciate and preserve forgetting as a feature of humanity. To do so may require us to adapt our digital tools. Unlike our brains, they can easily be rewired. With the help of the companies that design our online tools, we could let tweets and Facebook comments expire over time.We could choose the photos in our digital libraries we want to remember, and the e-mails we hold dear, as we let the rest slowly disappear; thus giving us a renewed and much-needed chance to forget.

This would preserve in the digital age our ability to grow, to learn and to forgive. And it would give us a better shot at having a rancor-free family holiday. That alone would be worth it.

Viktor Mayer-Schönberger, the author of “Delete: The Virtue of Forgetting in the Digital Age,” is a professor of Internet governance and regulation at the Oxford Internet Institute.

Viktor Mayer-Schönberger, author of “Delete: The Virtue of Forgetting in the Digital Age,” is a professor of Internet governance and regulation at the Oxford Internet Institute.