Mr. Lamb is successful in changing Derry's mindset. How did it become possible?

Mr Lamb observes that Derry had two arms, legs, ears and eyes plus a tongue and brain which meant that he would get on the way like all the rest. If Derry chose and set his mind to it, then he could get on better than the rest. He adds that he had a lot of friends even though he lived alone because he was always open to welcoming people. So, anybody could come and sit in front of the fire in the winter and kids came for the apples, pears and toffees. To him, people were never just nothing and they had their own distinct woes to deal with. Not every person with a burned face had the same issues to deal with. Everything was same but everything was also different. In Mr Lamb's opinion, our difficulties or flaws should not become the governing factors of our life because then bitterness and disappointment would seep into everything. Derry understood that he should not be selfishly absorbed in his own woes and also think about the possibility of suffering being differential in nature.