Gardner Raymond Dozois was an American science fiction author and editor. He was editor of Asimov's Science Fiction magazine from 1984 to 2004. He won multiple Hugo and Nebula awards, both as an editor and a writer of short fiction. Wikipedia entry: Gardner Dozois
Really interesting to compare this story with "Daddy's World" by Walter Jon Williams, but the Williams was entirely scene-dependent (appropriate to show a baffled child's dawning realization that his world is all wrong), while Dozois's protagonist had so much more introspection, again the right choice for his old man attuned to a world he knows he'll be leaving soon. There was more complexity to the Dozois, but they were both interesting.