Solution

Two different answers are possible. One is being given below:
Derry will not get back to his old seclusion. He has been associated with Mr Lamb for a short time only, but even this brief association will effect a change in the kind of life he will lead in future. Instead of being conscious of what people comment about the ugliness of his face, he will use his head and heart to achieve what he decides to do in life. It is also possible that with his firm determination and zeal to achieve his aim, he might do better than the rest, even those who do not suffer from any physical impairment.
By his persuasive manner and skilful use of anecdotes, Mr Lamb convinces Derry that a life of seclusion and withdrawal from the world is dull as well as risky. The world has many beautiful objects to see and admire, sounds to hear and ideas to think. One should have an open mind and positive attitude. Hatred is worse than acid.
Derry’s mother tries her best to keep Derry with her. But Derry resolves to go back to Mr Lamb to look at things and listen to him. He no longer cares about his face. What he thinks and feels, and what he wants to see and find out and hear is more important. He does not want to remain at his home. He has got clear perception of things. If he does not go back there, he will never go anywhere in that world again. In short, Derry’s coming back to Mr Lamb is indicative of the change in the kind of fife he is likely to lead in future.