Answer:
Jerry portrays his feelings about him being alone and sad. He feels upset and decides to do something about this. He moves away from his beloved mother and gathers his courage to hangout with a couple of boys near some rocks away from the main beach. At the start he shows himself as desperate and alone, but after a while he's being accompanied by some native boys he has started a conversation with.
Hope that helps..? x
Illusion. (n.) a false idea; something that one seems to see or be aware of that really does not exist.
It can make your paper more appealing to readers, and/or more informative for the readers as well.
As the title suggests, a treasure, but more specifically alluded in the plot, it's the pirates'treasure . However, a treasure is always the symbol to depict the immorality of that age when Stevenson wrote this novel of adventures.