I think the title could be " The return of memories", because the main topic is about memories. At the end they return to the people of the strange community. Perhaps you can get a better idea of the content.
Or the title of the book could be " Fighting for the truth", because Jonas has the mission to flee out of the community. He fights against the rain, the cold and other things. He has to hide from the people and it is a fight to reach the summit. It is also a fight to go in a unknown world.
I have a last title for "The Giver", maybe you can call the book " Revolution inside", because Jonas has the idea to change the society. He feels angry about the horrible system. With a lot of zest, he makes the way to exempt the people alone. And everything begins with an idea inside him. The revolution inside him.