As part of the decision to adopt Sameness in the community where Jonas lives, a number of activities that involved making choices were eliminated from the lifestyles of the community. Since such activities were no longer accepted or considered needed, they were removed from the school curriculum.
Music and art were cut out of the school's program, as was reading - all of these subjects allowed for making choices and were therefore unacceptable in the drive to develop a community that was completely predictable and controlled in every way.
The community of the Giver had achieved at such great price. A community without danger or pain. But also, a community without music, color or art. And books.
This is why Jonas was struck by the great number of books in The Giver's rooms when he went there the first time.
The subject of history was also cut from the curriculum. There was no need for the residents of the community to have any memory or awareness of past happenings - that was the reason why a Receiver of Memories was needed, to preserve that knowledge and use it to make decisions on behalf of those who no longer could make choices because they didn't have the experience and knowledge to do so.
There's much more. There's all that goes beyond – all ... that is Elsewhere – and all that goes back, and back, and back. I received all of those, when I was selected. And here in this room, all alone, I re-experience them again and again. It is how wisdom comes. And how we shape our future.