The first FPS game I started playing and studying was Wolfenstein 3D, but at the time I was still taking my first steps and was only producing tests,, but later with DOOM and DOOM II I had already made some good playable maps. Unfortunately at that time I saved everything on floppy disks, and with Quake I went crazy and never thought of saving it on a CD, and over time everything was lost.
Years later, when I worked in support for Openlink, an internet provider between 1997/1998 we had very bad machines for our personal use, and sometimes we had nothing to do. So at that time we started playing DOOM on LAN to pass the time. Yes, the first one, because it was the game that ran well. So I went back to making some maps for that old game, some very small test maps to remember how to do it, and one reproducing the Floor of the Teleport Building where we worked.
When I left that job I didn’t really care about saving those maps thinking I would never play DOOM again. From that point of view I was right, I never played DOOM again, but I would have liked to have at least that one map to put out there. Well, it wasn’t a big deal.