Step 1: Derry's initial attitude towards Lamb.
Derry, initially, is filled with self-pity and is reluctant to be around others because of his facial deformity. His negative self-image keeps him from wanting to open up to people.
Step 2: Lamb's influence.
However, Lamb's kindness, acceptance, and understanding towards Derry create an emotional bond. His warmth draws Derry towards him, and he begins to find comfort in Lamb's company, despite his initial resistance.
Step 3: Conclusion.
In spite of Derry's initial reluctance and lack of confidence, Lamb's personality and patience slowly begin to overcome his self-doubt, which draws Derry toward him.
Final Answer: \[ \boxed{\text{Derry is drawn towards Lamb because of Lamb's kindness, patience, and understanding, which helps Derry open up despite his initial resistance.}} \]