I thought myself pretty smart at many things, like holding my breath, running, jumping, or climbing the vines in Old Woman Swamp, and I wanted more than anything else someone to race to Horsehead Landing, someone to box with, and someone to perch with in the top fork of the great pine behind the barn, where across the fields and swamps you could see the sea. I wanted a brother. What does the imagery in this excerpt best show about the narrator