I still have some of the material I produced as a DM in HS in the second half of the '80's, a rewritten version of 'Keep on the Boarderlands', a n adventure loosely inspired by U2 but on a more epic scale, and a large number of hand written short encounters. I haven't looked at it in some time, so I'm not at all sure what survived exactly. It's not that well written, but the ideas aren't that bad. I was obessed at the time with providing myself lists - contents of pockets, titles on a bookshelf, inventory of armories, and so forth. Still am to some extent, and I've only lately been considering how to write a module in a way that someone else could play it and still fit it in a 64 page folder.
My older stuff from my elementary and junior high years was thrown out when I left college, and seemed hopelessly juvenile back then. Although there was some attempt to be more, basically my earlier adventures devolve down to 'There is an evil undead overlord that must be destroyed. In the first room are skeletons, in the second room are zombies, in the third room are ghouls...' Now that I'm older though, I tend to look at my inspiration for that time and go, 'No wonder.' Consider say the plot of 'Against the Giants', 'There is an evil overlord to be destroyed. In the first room there are ogres, in the second room there are hill giants, in the third room there are frost giants....' I also wish I had that stuff back sorta like a slide collection for a vacation. Painful to look at, no matter how good the memories were.
Not to mention there is nothing like a juvenile mind for creating painfully devious traps. I wish I had the outlines of the unfinished and unplayed uber-dungeons I was planning as a JHS DM. Looking through dungeons like RttToH or RA, I have to wonder how many of the ideas were stripped from the designers early years as a DM and polished off.