What do you think are the most important lessons Jonas learned from the Giver?
Jonas learns many lessons from the Giver, some small and some more significant. Let's look at two of the most significant lessons.
First, Jonas learns that the world is not what it seems. He learns this as early as the first receiving session in Ch. 11 when he learns about snow, hillsides, and color for the first time. The Giver explains that this is how the world used to be prior to the community going to Sameness, but the Giver also reveals that they have not "completely mastered Sameness" either, so color still exists in some things. The vast majority of the community, though, cannot see color. Jonas and the Giver both have that ability, and this is just one example of the world not being as it seems. Jonas comes to learn that there are "elsewheres" outside of the community, that "release" is actually group sanctioned lethal injection, and so on. All of these ideas challenge what he has always known about his community, which leads to the next most significant lesson.
Second, Jonas learns to question the world and people around him. This doesn't sound terribly significant to us as readers, being that we live in a world where we are taught to do this. However, in Jonas's community the citizens are taught from childhood to follow rules and authority very strictly, and this leaves little room for questioning the status quo. The Elders are seen as the ultimate decision makers and the wisest members of the community, so they are given the power to assign jobs, spouses, and futures for all members of the community. The citizens do not question their decisions or the rules that they craft. When Jonas begins to receive memories of a world before Sameness, he begins to question why anyone would have changed the world and gotten rid of certain things - like color. He wants to make his own choices, at least at first.
"If everything's the same, then there aren't any choices! I want to wake up in the morning and decide things! A blue tunic, or a red one?" (Ch.13)
As time goes on and he experiences more memories, feels emotions more deeply than those around him, and simply gains more experience, he cannot help but question the reasoning behind many of the actions the community takes. By questioning the world around him, Jonas begins to think critically - something else the citizens of the community gave up when they went to Sameness.