Once upon a time I had electronic and paper copies of all my early sales (as well as a great many stories that never sold). Over time, old files got packed away and, in the course of various moves, lost. Computers which held the electronic copies died and backup disks and tapes either turned up missing (one Zip disk of a set that had a computer backup as a spanned zip file--bad move on my part) or proved unreadable.
The result is that a lot of that early stuff, including all my published fiction from before 2005, is g. o. n. e. gone.
A writer friend of mine recently suggested that I might want to gather together my published fiction and put it together as an anthology. Self publishing or small press is a lot easier now than it was when I started and if I can do it it's basically found money. But since I don't have readable electronic copies of any of this stuff I basically have to type them all in again (I do have copies of the various magazines).
But aside from the published stuff, a lot of my early stuff is completely gone. Much of it is probably better off that way but some of it may still have had possibilities or could at least have been mined for ideas.
So my advice to writers is to back up your work. Make backups of backups. Have "off site" storage of backups. Have multiple off site storage locations for backups. Back up in more than one form.