“The fair boy said this solemnly; but then the delight of a realized ambition overcame him. In the middle of the scar he stood on his head and grinned at the reversed fat boy.

‘No grownups!’” 

Their world is turned upside down, but the fair-headed boy (Ralph) is delighted. He has ambitions, and now they will be realized. The implication here is that grownups have thwarted his ambitions. This is a foreshadowing of what is to come: without grownups, the fair boy will realize his ambitions. It is ironic that he is called “fair” here. Nature is fair in that the fittest survive, but humanity, the author is saying, should rise above such animal thought. The fair boy, however, does not think so, at least at this point in the novel.

“The fat boy waited to be asked his name in turn but this proffer of acquaintance was not made; the fair boy called Ralph smiled vaguely, stood up, and began to make his way once more toward the lagoon. The fat boy hung steadily at his shoulder.” 

In the beginning, Ralph doesn’t care about Piggy. Piggy, however, needs Ralph. He tethers himself to Ralph because he sees Ralph as a leader. Piggy is weak: he is fat and has asthma, which Ralph constantly makes fun of: “Sucks to your ass-mar!” (13). In the early pages of the novel, Ralph isn’t a leader, and he isn’t fair to Piggy. He is delighted that there are no grownups. Later, when he sees that he needs Piggy, he will be kind. In this passage, he does not yet know that he will have to be the one to grow up.