Step 1: Recalling the Text:
Mr. Lamb represents an alternative, hopeful way of facing a difficult life, which contrasts with the fear and rejection Derry usually experiences.
Step 2: Explaining the Attraction:
His non-judgmental warmth, philosophical outlook on courage and freedom, and genuine interest in Derry as a person (not his appearance) formed the basis of their bond.
Final Answer:
Derry was drawn to Mr. Lamb's genuine warmth and refusal to judge him by his appearance, and to his fearless, optimistic outlook on life despite his own disability — qualities that made Derry feel truly accepted for the first time.