That is awesome. I love hearing about how others encountered certain games. Everyone's story is unique and interesting.
I only discovered Commander Keen years, well over a decade, later myself. I was not much of a PC gamer when this one hit, well not what passed as "modern" at the time. I was still rocking a Color Computer II in 1994 (wrote several poetry books and short story collections on that bad boy).
RE: Commander Keen Takes a Negative from Nintendo to Create a Classic on Computers – Today in History – December 14th, 1990