What do maps come to represent for Craig during his stay in the psychiatric unit in the novel, It’s Kind of a Funny Story?

In an art therapy class, he begins drawing maps, a practice he enjoyed as a child, and at the suggestion of a fellow patient, he draws the outlinie of a head around them and turns them into brain maps. Eventually, the maps become an Anchor for him and a way to understand his own problems and the lives of his new friends on the unit.