Why did Sophie like her brother Geoff more than any other person? From her perspective, what did he symbolize?

Sophie liked her brother Geoff more than any other person, he was the only person who would listen to her fantasy stories with patience and she believed that he knew more than her about the city, people, and other things that she was always interested and fascinated to know about. She was jealous of his silence and she knew he was grown up always thinking about the surrounding things in the world.