Time and Time Again

Isn't it interesting that what we perceive as reality is actually only what our mind processes and sends us to act upon? In the story, Time and Time Again, Dr. Al Hart, a professor and university administrator, is living two realities at the same time; one life he accepts as real, but the other, equally realistic, exists in a different time and place. In the life he accepts as real, he finds himself an invalid unable to speak and barely able to move in an Alzheimer's assisted-living facility, wondering how he got there, and if the events he recalls from his job as a university administrator caused a stroke or pushed him into madness. He remembers everything about his life up to the point of entering the 'geezer garage' (as he calls this assisted-living facility), but nothing of his "other" life except what he reads. In the other life he is a whole and active man who finds himself, with his dog, lost in a new time and place dealing with the consequences following a long past nuclear disaster and the earth's first contact with a superior alien intelligence. Dr. Hart types his unread story on a personal computer in the 'geezer garage', alternating chapters between each life, but even in his mind the question remains; is either life actually real?