A friends housemate had a computer, very fancy, dual floppies think it was branded as "SuperBrain" or something. He showed me Modula-2 which would would render Pascal obsolete and assured me CPM would never be replaced as there were too many programs already written for it. It was all way over my head, but he had this game "Adventure" on it ... about a week or two later it dawned on me that navigating the cave and saying magic words all by typing was really no different than navigating the file system and issuing commands and if I could do the one I could do the other. Stopped playing that game and started this one, no regrets.