All children, except one, grow up. They soon know that they will grow up, and the way Wendy knew was this. One day when she was two years old she was playing in a garden, and she plucked another flower and ran with it to her mother. I suppose she must have looked rather delightful, for Mrs. Darling put her hand to her heart and cried, "Oh, why can't you remain like this for ever!" This was all that passed between them on the subject, but henceforth Wendy knew that she must grow up. You always know after you are two. Two is the beginning of the end. (Chapter I, "Peter Breaks Through")

Here we have the very beginning of Peter and Wendy, the original Peter Pan story. Poor little Wendy realizes that she's going to have to grow up one day.

Peter and Wendy opens by drawing a distinction between children and adults. We might remember that this distinction wasn't always taken for granted, and in this passage, we see Wendy realizing that being a "child" is different from being an adult.

The passage puts childhood right at the center of the story. It's great to be a two year old, and we feel Wendy's sadness when she realizes that she won't always stay the way she is. That innocence about time and growing up, of course, is itself one of the characteristics of childhood.

Notice how this excerpt begins with a mystery: "All children, except one, grow up." There's a child out there who doesn't grow up? That very first sentence hooks us into the story.