Why does Jem make a new theory on boo rarely?

Jem makes a new theory on Boo Radley rarely because he starts to see him in a different light after witnessing his act of kindness towards Scout. This challenges Jem's previous fearful perception of Boo and prompts him to reconsider his assumptions about Boo's character. Additionally, Jem's growth and maturity throughout the novel allow him to develop a more empathetic and understanding perspective towards Boo.