When the last Receiver of Memories failed, the memories that she already possessed were released and lost. "It was chaos," the Giver comments.
"They really suffered for a while. Finally it subsided as the memories were assimilated. But it certainly made them aware of how they need a Receiver to contain all that pain. And knowledge." (Ch.13)
The Giver's explanation causes Jonas to reflect upon his new position in which he will be forbidden to reveal his knowledge unless called upon by the Elders. So, there would be a major part of his life that he must keep secret. Also, he learns from the Giver that rarely does the Committee of Elders call upon the Giver for advice, although he would really like to advise them, and even suggest their doing some things. But, the Giver observes, "[L]ife here is so orderly, so predictable—so painless. It's what they've chosen." (Ch.13)
Further, when the Giver mitigates what Jonas's science instructors have taught him about the brain, saying, "They know nothing," and insisting that the most important thing in life is memories, Jonas is shaken.
Indeed, this is a pivotal moment in the development of Jonas's character as the Giver's tale of the previous Receiver and his remark about the importance of memories, plants a new seed of thought in Jonas which then furthers the narrative, as well.