Nothing ever really happens.
-- Sarah (The Tornado)

Importance: In the opening line of the book, Sarah tells the reader that "nothing ever really happens." She means this both in the sense that nothing literally happens and that much of life and the way we remember our experiences do not happen the way we remember them and that nothing happens figuratively. That is, life is a series of the same thing over and over. This is important because there are portions of the book that will test the reader's understanding of reality. Things that the reader originally believe happened (like the fish in Mexico) are exposed as a story Sarah made up, while things that should not be able to happen (like the multiplicity of Sarahs in the story) actually do happen. The quote calls attention to the difference between reality and truth.

The whole world thinks sixteen-year-old girls are dramatic and silly anyway. But...
-- Sarah (Umbrella)