This poem by Robinson explodes in the final lines. He describes a young, charming male, who seems very much social and active. However, the last line throws off every bright belief that the audience has developed for the guy.
Robinson creates a deeper impact on the minds of readers by creating a bubbly image of Cory and then, showing his final action which blows life out of him. This 'show' in the closing line pierces the minds and hearts of the readers and they understand- "all that is bright is not gold." This end introduces the audience to the ultimate emotion that was hidden behind the happy face of Mr. Cory. The themes of sadness, greater pain and loneliness are highlighted through this.