Why is John Coogan called crash?

Crash, the protagonist, is 5-years-old at the beginning of the story. He's sort of a cautious boy who is not over-eager to expand his horizons. When Penn and his family move in next door, they intimidate Crash with their foreignness. Even though they're only from North Dakota, they're speech and lifestyle is strange to Crash. In response, he bullies Penn. Crash continues to resist things that he cannot understand -- like his sister's passion for entymology -- until his grandpa has a stroke. Crash doesn't have many friends besides Mike, so losing his intimacy with his grandpa is a big deal. Although he doesn't understand it, he appreciates Penn's kind attention paid to the old man. He starts paying attention to what may be important to other people, like Penn. Eventually he realizes that Penn deserves a win too, so he lets him win an important race in school to make his great grandfather proud.