Back when people still bought CDs and streaming media was a slow and frustrating experience, my teenage band recorded a number of average songs and put them out. I have copies of two of the three EPs we released. What didn’t get committed to those low-print-run, landfill-fodder discs was uploaded to our MySpace and left to float in the digital forever of the internet.

Two weeks ago, MySpace announced on their front page that everything uploaded to the site between 2003 and 2015 had been lost in a botched “server migration project”. The entire golden age of MySpace (and several years after the golden age) has been wiped, including an estimated 50m songs from 14 million artists. It may have happened as far back as a year ago, but MySpace have kept quiet. Some were sceptical it was an accident. “We apologise for the inconvenience,” Myspace said.

Very few people use MySpace any more. But in that 12-year period, Myspace was an unprecedented repository of the ephemeral products of endless subcultures, from fashion to memes to music. Some artists shouted into the void, and no one listened. Others, like Lily Allen and Arctic Monkeys, had more success.

For some, our instinctive urge to record and archive everything, from long-abandoned electronic music projects to how nice our hair looks today, is a relatively new and unhealthy one. And for many, what was lost last month was the detritus of the early age of social media, and an inconsequential period for popular music. Who cares about a bunch of emo bands from 2005?

Well, people do. But that’s not the point. Our predictions of what will be significant for future cultural historians are always wrong.

In television archives across Australia, from the National Film and Sound Archive to Channel 10, things are patchy prior to about 1976.

Videotape took up space, and most of it was in black and white. It could have no conceivable use. So entire series considered not worthy of preservation were wiped. This happened all over the world. Locally, almost all of music series Countdown from 1975 to 1978 is gone, including early appearances from AC/DC and Elton John.

Molly Meldrum, who cared deeply about what he captured every week on Countdown, knew it was short-sighted. He and other ABC staff did what they could to protect the tapes, including hiding them in their car boots.

Soap operas may be considered an embarrassing cousin of current prestige TV drama, but in a century, it’ll be episodes of Neighbours that people look to for a glimpse at early 21st century Australian neuroses. While 1957 episodes of Christian soap opera The House on the Corner may not have seemed of much use in the 1970s, they’d be a fascinating cultural resource now. If they existed.

In the UK, Bob Dylan’s first acting role, in a 1963 television play called Madhouse on Castle Street, is gone. Early Beatles performances on Top of the Pops too. Most of the BBC’s Apollo 11 moon landing coverage is gone.

Bits and pieces of lost TV are frequently recovered. What was mundane 50 years ago now has historical significance. Historian and archivist Philip Morris, the self-styled Indiana Jones of archival TV, travels the world looking for old tapes, finding Doctor Who in a Nigerian relay station and Morecambe and Wise in an abandoned cinema in Sierra Leone.

But most is gone for good. It is cultural neglect on a scale we can’t quite fathom. And it continues.

Things were supposed to be different by 2005. Media was replicated, downloaded, backed up and stored. In many cases there will be physical copies of what was lost, on scratched CD-Rs, on minidiscs and dusty disconnected hard drives at the back of cupboards.

The partial recovery process has already begun. On Thursday Archive.org announced the “Dragon Hoard”, a 450,000 song archive scraped from MySpace’s post-golden age of 2008-2010, accessible by download and searchable through an unwieldy, slow media player.

But it accounts for 1% of what was lost. The rest is a mystery. And when those 99% of artists go back to their shelves, their CDs, their attics, many will discover cracked, empty CD cases and dusty, corrupted hard drives.

If it wasn’t negligence, it’s an act of cultural vandalism akin to those shortsighted TV executives who destroyed years of cultural history to clear some shelf space.

Today, 2005 occupies that awkward space between recent past and embarrassingly dated. Is the loss of a few tracks by my teenage band a great loss to future musical historians? Out of a dutiful sense of modesty, I’m going to say no. But what value will the future place on, say, a Japanese witch house band, or an EDM producer working from her mum’s spare room in Bunbury, WA? Only time and hindsight will show us what we’ve really lost.