I was once without the sense of smell and taste for several days. It seemed incredible, this utter detachment from odours, to breathe the air in and observe never a single scent. The feeling was probably similar, though less in degree, to that of one who first loses sight and cannot but expect to see the light again any day, any minute. I knew I should smell again some time. Still, after the wonder had passed off, a loneliness crept over me as vast as the air whose myriad odours I missed. The multitudinous subtle delights that smell makes mine became for a time wistful memories. When I recovered the lost sense, my heart bounded with gladness. It is a fine dramatic touch that Hans Andersen gives to the story of Kay and Gerda in the passage about flowers. Kay, whom the wicked magician's glass has blinded to human love, rushes away fiercely from home when he discovers that the roses have lost their sweetness.
The loss of smell for a few days gave me a clearer idea than I had ever had what it is to be blinded suddenly, helplessly. With a little stretch of the imagination I knew then what it must be when the great curtain shuts out suddenly the light of day, the stars, and the firmament itself. I see the blind man's eyes strain for the light, as he fearfully tries to walk his old rounds, until the unchanging blank that everywhere spreads before him stamps the reality of the dark upon his consciousness.
What event does Helen Keller describe in this excerpt "values of the senses"?