Why does holden thing of James castle when phoebe asks him to name one think that he likes a lot?

Holden thinks of James Castle when Phoebe asks him this because James was a boy at their previous school who stood up to bullies and jumped out of a window to avoid being bullied. Holden admires James for his courage and integrity, and the memory of him highlights Holden's own desire to protect innocence and stand up against cruelty.