Answer:
The narrator always described Doodle as being a disappointment because of his large head and tiny, shriveled body so therefor Doodle cannot complete the physical feats that the narrator wants Doodle to perform. Also The narrator cannot stand the idea of having a brother who is not "all there". He also gets tired of Doodle's incessant questions.
Step-by-step explanation:
It was always anticipated that Doodle would die in infancy.