I seriously can't remember! I know I ran Gamma World when I was around 14. I was already creating notebooks full of dungeons at that point, because I still have one or two of them. But I can't, for the life of me, actually remember running them. I think it was just so normal a thing that it wasn't worth remembering. There are definitely "signs" that my dungeons were used (HP tracking notes in margins, etc...), so I wasn't just creating them for fun. By the time I was 16-17 I was running games a LOT, and I've been mostly a DM for my adult life.