The story is basically saying that we can learn from our elders, because they have been around longer and have more experience than us.
You can see this when it says "the tree is older than you are...you might find stories in its branches".
Jack and Ralph disagree over leadership styles and the priorities of what must be done on the island. Ralph feels that building the shelters should be the group's biggest priority; he worries about the littluns who do not sleep well at night and the possibility of more bad weather. Most of Ralph's frustrations stem from not having enough help from the other older boys on the shelters. They all agreed in the meeting that it was a good idea, but the actual implementation has been more challenging.
When Ralph asks Jack to help with the shelters, Jack refuses, saying that meat and hunting is more important to the tribe. After the boys debate that their island might not be a "good island," the boys come to an understanding that they both want different things, but the issue remains unresolved as to which is more important.
Answer:
He wanted to get to the water.
