Solution

Sophie's long-cherished desires and dreams are only heard by Geoff. Her father is overly pushy and overbearing. He despises Sophie's amazing tales. Even young Derek makes fun of her increasing wealth. Jansie, one of her classmates, is "nosey" and shouldn't be trusted with a secret. Only Geoff can be relied upon to keep all of Sophie's secrets to himself.
From her viewpoint, Geoff represents an older brother who has matured and been to locations she has never been. She hoped one day her brother would take her to such locations. He is kind and warns her that Casey could be a stringer of females.
He reminds her that he will never return. In order to spare the young dreamer's heart, he talks lightly.