In Maria Tatar's "The Annotated Classic Fairy Tales", the transformation of the little mermaid from sea creature to mermaid in human form, and then to a creature of the air, is believed to reflect Andersen's constant engagement with mutability and changes in identity. Tatar also suggests that the Little Mermaid did not give up everything for love alone. Tatar's interpretation of the tale is one that presents a rare heroine with an investigative curiosity which is shown through the mermaid's fascination of the unknown, the forbidden, and her intent on broadening her horizons from the start. Even before she sees the prince, she displays an intense longing to visit the world above the sea through her actions such as: arranging the flowers in her garden into the shape of the sun, listening to her grandmother and sisters' stories of the surface, and peeking in through the window of the prince's cabin during his birthday celebrations. Tatar argues that the mermaid wants, above all, to explore the world and discover things that are beyond what she already knows. The world above seems larger than her own and holds a greater range of possibilities to exercise her adventurous spirit. This is demonstrated in some versions of the story when the prince has a page boy's costume made for her so that she may ride on horseback and explore the land with him. Here, her willingness to cross-dress implies a willingness to transgress gender boundaries and take risks to be able to see the world. Tatar feels this also comments on Andersen's interests in changes in identity.