Equality
The title of the book does give a hint, but the way Susin Nielsen writes that we are all the same is simply amazing. Under all of our quirks and opinions, we are all simply human, all made of molecules. This theme is quite apparent in the book as two people who are completely different cross paths and decide to hate each other - at first. When Ashley and Stewart start to realize that their interests, being popular and academics, respectively, are not everything, they can begin to form a close friendship - after all they live in the same house now. Susin Nielsen wanted to make it apparent that we should treat each other as equals because, after all, we are equals.
Learning to Cope with Differences
In the novel, Stewart and his father move into a house with Ashley and her mother, threatening Ashley's reputation at school. Stewart, on the other had, is a very smart young man but is stereotypically regarded as a nerd and subsequently bullied. If people at school find out that Ashley lives with a nerd, what will they think of her? It soon becomes apparent that she cannot do anything about the situation - her mother is in charge here. Throughout the course of the novel, Ashley gets used to living with Stewart, and in that process accepts him for who he is. She even begins to get better grades, with his help. For everyone, a new situation can be threatening, or even embarrassing, but learning how to cope with those situations is what makes the epic saga of life so amazing.
Popularity Isn't Everything, and Neither Is Smarts
Both Ashley and Stewart lack and yearn for what the other yearns for, and start to realize that they need to work together to get the most out of themselves. Ashley, who is so reliant on being popular for her entertainment, begins to realize throughout the course of the novel that she won't be able to get anywhere in life just by being able to talk to people - plenty of people already do that. Stewart realizes that he also can't do anything by being intelligent - he needs social skills. To be a complete person, you need both of these things, and Nielsen hopes to portray this to readers who may have similar problems themselves.
