How does the author use foreshadowing in The Old Man and the Boy?

In Chapters Four through Six, the narrator foreshadows a day far removed from his childhood, when he is living an exciting life, undreamed of in his young days on the Carolina beach. He comments that the Old Man is long dead. He also refers to a day, twenty-five years after killing his first buck, he experiences a similar feeling after shooting a buffalo on the African savanna. It seems that the Old Man, through his lessons of nature and hunting, has been trying to prepare the Boy for a day when he can use those skills in any environment, even without his grandfather.