When Palmer attends the pigeon shoot this year, what does he come to realize about his memories of shoots from years passed?

Palmer thought the pigeons flew from the boxes into the sky and were shot down from high in the sky. Now he sees many of the pigeons are shot while walking out of the cages or pecking on the ground for food. The ones that do fly only fly as high as a man's shoulders. The killings, he realizes, could be done with a baseball bat. His memories were ones of a small child viewing the shoot rather than an older one.