Final answer:
The best teacher Holden ever had in 'The Catcher in the Rye' is the man who mends his fencing mask and shows him kindness and care.
Step-by-step explanation:
The character that matches the description of being the best teacher Holden ever had, whose compassion for his students confuses Holden, is The man who mends Holden's fencing mask in the novel 'The Catcher in the Rye' by J.D. Salinger.
This character shows kindness and care towards Holden by fixing his broken mask and discussing life lessons with him during their encounter. Holden struggles to understand why someone would go out of their way to help him and is touched by this seemingly simple act of compassion.