What is the theme in The Elegance of the Hedgehog by Muriel Barbery?

Hiding one's true nature is a theme. This novel is about a woman who feels she must hide her true nature because she thinks that the wealthy people in the building where she lives have certain expectations about their concierge. Renee enjoys her job and does not want to lose it because the job gives her the time she desires to read and watch artistic movies. For this reason, Renee becomes quite frightened each time it seems someone has discovered her true nature.