The adolescent Holden suffers intensely from survivor's guilt after the leukemia death of his brother Allie. This fuels in Holden an intense desire to atone for this death, even though it was not his fault, by protecting other innocents. These include people like his friend Jane Gallagher and the nuns he meets while breakfasting in a diner. However, his focus is on children, especially his little sister Phoebe, but all children in general.
As Holden tells Phoebe, he wishes he could be the catcher in the rye, the mythical figure who stands at the edge of cliff and saves the children playing nearby who might be in danger of falling off.
Towards the end of the novel, Holden ends up in two of his childhood haunts, the Metropolitan Museum of Art and the Natural History Museum. At the Met, he helps a group of rough boys find the Egyptian mummy exhibit. At the Natural History Museum, looking at the dioramas, the innocent period of his childhood field trips comes flooding back to him. He wishes he could be be back there, with no more troubles than who his partner would be on the trip.
However, encountering the past also helps Holden deal with it. By the time he lets Phoebe ride the carousel and grab the gold ring without hovering over her fearfully, he realizes, as he puts it, that the
thing with kids is, if they want to grab for the gold ring, you have to let them do it .... If they fall off, they fall off, but it's bad if you say anything to them.
This shows a maturation in Holden from the night before, when he wanted to protect children from falling. Now he realizes that life is risk and that children like Phoebe can't grow if they are not allowed to take some risks. The cycle of life, symbolized in the circular motion of the carousel, involves both the pleasure of the ride and the risk of falling.