How does golding show that Ralph is beginning to forget what up to now he has concidered to be their most important gaol?

When Ralph tries to give speech about how fire is important to the rescue, he actually forgets what he was talking about in the middle of his speech. Language degradation shows how the boys, even Ralph, is becoming more savage. Also, forgetting what he was saying is one of the symptoms of mental breakdown. Ralph is worn out because of the immense responsibility given to him.