On your computer, you really don’t ever take out the trash. Data doesn’t get picked up by a garbage truck. It doesn’t decompose in a landfill. 

“It’s just there,” says Judith Donath, an author and scholar of social networks. “Even if you don’t think about it, all this stuff accumulates.”

She calls this problem digital hoarding.

“It’s sort of like the person whose house has slowly filled up with mail and circulars and newspapers and bits of furniture and the things that a renter left behind years ago because they just didn’t make the effort at some point to go through it and throw it out.”

We’ve all thought about going through those old files to see whatever bits of our old selves are left there. Jack Cushman actually did.

He’s a fellow at the Berkman Center studying the digital archives of Harvard researchers. The hard drives of academics contain a ton of really important data which poses a problem if you want to save it all.

“I’ve been working on how you preserve these kind of massive digital repositories that we all create without thinking about it, that for us are just the trash,” Cushman says. “We’re going to retire and we’ll delete that and we’ll never think about it again, but that 50 years from now someone is really going to care about.”

As Cushman was working on this problem, he was also moving and going through old boxes and found three old hard drives. And being a digital archivist, he took a look to see what was on them. The files on one of them had been erased on September 10th, 2001.

“What it looked like was a fresh new Windows drive, but then back behind it were these scraps of old files that had been created and lost… Among those I found, for example, exactly three emails that were not complete emails, but just parts of the files. I found these three emails that I had exchanged with my first girlfriend in 8th grade.”

Cushman created all of this data whether he was aware of it or not. And even though he forgot about them and even tried to delete them, they still exist somewhere just as they were. But in pieces.

“In the past the default has been to forget and the exception was to remember. And that default was built into our brains,” says Viktor Mayer-Schönberger, an Oxford professor. He’s also the author of “Delete: The Virtue of Forgetting in the Digital Age.”

He says that as people transitioned into a more digital world, one of the things we embraced was the ability to retain everything. Suddenly we had unlimited memory.

“All through human history remembering, capturing stuff was hard, was time-consuming, was costly,” Mayer-Schönberger says. “And so now we are like a kid in the candy store and we indulge in our ability to create digital memories, up to the point where we realize that too much of a good thing actually is a bad thing.”

Now what you’re seeing is an evolution in the type of tools we use to store and deliver memories. For example, Mayer-Schönberger says his students will use Facebook for what they call “press releases.”

“Posting stuff that they want their future employers or grandparents to see. That is the kind of curated persistency they want for some pieces of information.”

But for other, often social stuff, like pictures out at the bar, they’ll use an app like Snapchat that deletes data automatically.

According to a Pew Research Center study released in August, 41% of smartphone owners ages 18 to 29 use apps that automatically delete sent sent messages.

So if Jack Cushman were a teenager today, there’s a good chance he wouldn’t have exchanged many emails with his girlfriend at all. 

In fact, finding the remnants of the digital conversations between teens today would be a lot harder. 

Snapchat’s founder, Evan Spiegel, said his larger hope for the app is that it’ll allow people, not just teens, to share photos without feeling like they’re curating their own “super-boring” permanent records. And that was in 2012.

In the years since, we’ve seen politicians tweet naked photos of themselves. We've seen the fallout from the Sony email leak. And we've seen millions of names released from a website designed for those who want to have an affair.

In other words, kids these days have seen scores of adults hurt by the data they launched into cyberspace and forgot about, maybe even tried to delete.

Even Cushman, when he uncovered all that data, said he found stuff he didn’t necessarily want to see again. 

“That revealed me to be somebody that in 8th grade read a lot of science fiction books and really never talks to human beings. And that absolutely I will never reveal to the world.”

That’s kind of the problem with digital memories says Mayer-Schönberger. Your past self is presented to you just as you were without the years of experience and change stored in your brain. “With digital memories we have difficulties shedding our past even though we as human beings may have changed as we are doing all the time.”

He says, psychologically, forgetting performs a really important function. It allows us to forgive and grow as people.

“To me it all comes down to the issue of trust,” Mayer-Schönberger says. “Trust that we have in our digital tools, in our digital services to accept us as the human beings we are, as the changing entities that we are.”

And even with tools that delete by default, Judith Donath says she’s not ready to trust the tools we have today.

For example, does Facebook know what pictures, statuses and memories you want to retain from 2013?

“[Facebook will] just post, ‘here’s some highlights from your previous year’ without recognizing that that’s probably not the best job for a machine to do,” Donath says.

With better tools, she says companies could help you sift through your digital stuff; your old emails, your photos, your tweets and timeline posts, and help you better understand the most important patterns and highlights.

“I think that’s the problem that we face is trying to preserve enough of the digital record that we’re laying down things of value,” Cushman says. “And maybe an important part of that is giving people to make their own preservation choices about the things they’ve created.”

For the first time in probably the history of man, deletion isn’t the default.

It’s a world where everyday conversations between two 15-year-olds can be perfectly preserved for a decade.

And in this digital record you might be making decisions about what to keep forever and what data would be better stored as an old-fashioned memory.

This piece was produced with the Berkman Center for Internet and Society at Harvard University. Special thanks to Radio Berkman producer Daniel Dennis Jones.