P., a music teacher, whose associates have questioned his perception, is referred by his ophthalmologist to the neurologist Oliver Sacks. During the first office visit, Sacks notices that P. faces him with his ears, not his eyes. His gaze seems unnatural, darting and fixating on the doctor's features one at a time. At the end of the interview, at which his wife is present, P. appears to grasp his wife's head and try to lift it off and put it on his own head. "He had . . . mistaken his wife for a hat!" She gave no sign that anything odd had happened.

During the second interview, at P.'s home, P. is unable to recognize the rose in Sacks' lapel, describing it as "a convoluted red form with a linear green attachment." He is encouraged to speculate on what it might be, and guesses it could be a flower. When he smells it, he comes to life and knows it. The wife explains that P. functions by making little songs about what he is doing--dressing, washing or eating. If the song is interrupted he simply stops, till he finds in his sensorium a clue on how to proceed.

This cantatory method of compensating allows P. to function undetected in his professional and personal life. He remains unaware that he has a problem. Sacks chooses not to disturb his ignorant bliss with a diagnosis. Though his disease (never diagnosed but hypothesized as a tumor or degeneration of the visual cortex) advances, P. lives and works in apparent normalcy to the end of his days.