Earlier this week, Miracle Mattress in San Antonio put an ad on the Internet to celebrate a September 11-themed sale: “What better way to remember 9/11 than with a Twin Towers sale?” a woman asked, while two men helped explain how the deal worked: you can buy a full-size, queen, or king bed all for the price of a twin. (Get it?) Then, to make sure that the point was driven home, she threw her arms back, ostensibly knocking her colleagues over and sending them crashing into two towers of stacked mattresses, which toppled. Finally, she turned to the camera with a smile to say, “We’ll never forget.”

It didn’t take long for Miracle Mattress to receive blowback on the Internet. The ad is a bizarre display of irreverence for the 3,000 people who died on September 11, 2001, as well as the 7,000 more who were killed in the wars that followed the attack. Miracle Mattress quickly apologized, explaining that their “intentions were not to hurt anyone at all,” and that “Our staff is full of military and some relatives have passed away due to 9/11. We are promoters of peace and love. We have given abundantly to our community here in San Antonio and wish to remain known as a company who respects and loves others. We hope you find it in your hearts to forgive us. Please accept our apology.” The store’s owner issued a further apology, condemning the employees responsible for the video.

The consequences for those employees haven’t been revealed, but one can assume that they’ll be serious. That’s fair, given the damage they’ve done to the brand of Miracle Mattress. But the solemn way we remember 9/11 is something that is likely to change in coming years, if only because the people who create the ads and other media that we consume are going to have a very different relationship to the events of that day. Right now, an intern at an ad agency might have been five-years-old on September 11, 2001. In a few years, we’ll see things created by people who weren’t alive at all on that day. For them, the events of 9/11 will only fall under the category of history, never having been a current event.

That doesn’t justify an ad like the one from Miracle Mattress, or similar gags that make light of September 11. It just means the further that the shock of that day falls into the rearview, people who have clear memories of both a pre-9/11 America and watching the towers come down in real time are going to exist in a world with other adults who have only learned about it. We can hope that those folks will respect the emotions that invoking September 11 brings up for people whose reactions are visceral and personal, but that’s not usually the way that youth and humor work. They make holocaust jokes in Israel these days. The last generation’s unspeakable tragedy tends to be something that the next generation thinks is kind of funny—or, at least, that joking about it is a satisfying taboo to break.

A theme in the years to come, as 9/11 hits its fifteenth anniversary and beyond, is that younger people will figure out what their own relationship to that day is. We’ve seen it play out clumsily before, like when Lumberton High School’s cheerleading team performed a routine honoring those who died when they were in diapers. We’ll see it play out offensively, as people with even less connection to 9/11 than the people in the mattress store ad (who appear to have been old enough to form memories when the hijacked planes crashed into the towers) find themselves in the role of creating content.

We’re certainly a culture that enjoys irreverence, and that’s especially true of young people making things for the Internet (peace to Harambe). It might be hard to watch the ad for Miracle Mattress without being upset if you remember, say, calling friends and family in New York and Washington, D.C. on that day in September 2001 to find out if they were alright, but in the years to come, you’ll probably see it happen more frequently. They say that comedy = tragedy + time, and as the years march on, we’re likely to see a lot more people go to this particular well for their jokes.