I took two readings of The Catcher In The Rye to understand the whole point of it. At first, I thought all that went on was Holden saying "sonuvabitch" and whining about phonies. Only upon reading it again that I learned that it was a tale of Holden stuck between childhood and adulthood. —Ray Ayanami
Another popular theme is that Holden suffers from PTSD from his brother's death, and the end is him finally realizing he needs help