The titular slider symbol represents David’s family, developing the theme of The Importance of a Family Support System. This symbol appears in two key places within the novel, and its meaning shifts as David’s perspective on his family dynamic changes. In Chapter 4, David introduces this symbol, saying, “I label myself the beef in a SooperSlider” (18), which he explains is like a White Castle burger with steamed meat. He says, “Being the middle kid of three is like being the beef in a SooperSlider—you’re just there to weld the bun together” (18). David compares himself to the meat in a slider because he sees himself as essential yet seldom appreciated. David’s symbolism communicates his belief that he is the forgotten middle child, despite his essential responsibilities to the family, like taking care of Mal. However, the symbolism of the slider becomes more positive at the end of the novel, when David revisits his previous perspective and decides that being the center of the family is “Mal’s job” (275). At this point, he celebrates the fact that his family will always come together to take care of Mal. David now sees himself as being just as important as everyone else in the family.