The Giver asks Jonas for forgiveness after transmitting a painful memory of war in chapter 15 because the memory is too difficult for him to bear. Moreover, war is one of the horrors that Jonas’s society has eradicated by controlling people in The Giver. Jonas therefore has no framework to even understand why people would harm one another this way.
The reader sees most of the rules and controls in Jonas’s society as oppressive ones that eliminate individuality. Some changes, such as climate control or the elimination of colors, even imply that people sacrifice certain pleasures, such as the enjoyment of the different seasons when the leaves change colors or the first snowfall. In fact, because of their controls, people no longer even see colors at all. However, one positive outcome produced by the controls, strict adherence to the rules, and the goal to achieve “sameness” is that the society has eliminated war.
Jonas cannot even understand the concept of war when he first receives the memory from the Giver. Many of the other memories that Jonas receives make him long for the society in which people are free to make their own decisions and families love one another. However, the memory that the Giver transmits in Chapter 15 is so horrible that it would have been difficult for anyone to accept, let alone a young man who lives in a society where such concepts are unthinkable. For Jonas, who is at the earliest stages of his training and lives in a world where there is no war, the memory is horrific and hurts him physically.