What is the theme of this book? Explain why that is the theme

I think that identity is an important part of the book. In many ways, this is a coming of age story. Misha is is discovering adolescence during a time, WW2, when identity can get one killed. Misha is a Jew who by deffinition is persecuted by the Nazis. Misha also has no idea where he came from or who he is.