What are the motifs in The Canal by Richard Yates?

This story suggests that interpretation is subjective. Readers see the memory that Lew Miller has but does not share at the cocktail party, a memory that shows him in a negative light. But Yates also provides details about Miller's past which Miller does not emphasize, which might modify Miller's judgment of himself. For example, Miller dwells on the anger of his commanding officer, on feeling demeaned by him in front of the other soldiers. He is ashamed of the small failures, his losing his raincoat, his getting separated from his men, and over all, he remembers Kavic's caustic criticism.