In my entry, the value is achievement. The quote used to title the short story explains the difference between rational and irrational fear. This leaves the situation in the story open to interpretation for the reader, who may not believe that going to the dentist is scary at all. However it is clear that going to the dentist is causing a huge amount of anxiety for the narrator.
By the end of the story, the narrator has managed to go to the dentist and overcome the fear. This represents how we are capable of successfully progressing through our worries when they feel so physical in our bodies.
In any anxiety provoking situation, no matter what somebody else thinks about it, it is an achievement when a person is successful in overcoming that fear. The use of this common situation to represent this hopefully allows more readers to understand the physical feelings that come with fear and anxiety, and understand the effort and commitment to overcoming them.