movie castaway

In the movie castaway with Tom Hanks, I am wondering what the significance was with the one box he never opened, and why he said it saved his life.

it had a logo of feathers with Wind swirling around them, and it gave him the idea of the sail for the sail on his “boat”

For your enjoyment:

Question about Cast Away–spoiler

Since there is already a thread on this topic, I’m going to close this one.