What has happened to Jonas since he stopped taking his pills in The Giver?
When young people in the community reach puberty, they are prescribed pills to take for the Stirrings. The Stirrings are feelings of sexual attraction, such as what Jonas feels toward Fiona in his dream. The pills suppress these feelings.
Jonas becomes exempt from taking his pills after he is named The Receiver of Memory. He does not take his pills for a period of four weeks, and eventually the Stirrings return. He struggles with feeling "a little guilty and embarrassed about the pleasurable dreams" he has when sleeping. The absence of such dreams would mean the absence of feelings. Jonas no longer has to suppress his feelings, be they sexual or otherwise. In addition to the Stirrings, "heightened feelings [permeate] a greater realm than simply his sleep." He thinks that these new feelings come from both not taking his pills and from his newly acquired memories. He begins to see a wide array of colors everywhere. These colors are no longer fleeting. A world of color begins to surround him all the time. Jonas begins to think about Elsewhere. He also experiences feelings with a new sense of depth. Through the memories transferred to him by The Giver, Jonas starts to know true rage, grief, and joy.
The purpose of the pills was to stop all feelings of sexual attraction or awareness. When Jonas stopped taking the pills, he regained the ability to see and recognize the differences between males and females and to react differently to different persons based on such factors as physical appearances. Jonas has resumed having dreams, including dreams about Fiona, since he stopped taking his pills. Jonas, who already had the ability to detect color differences, is being helped by the Giver to understand the attraction of colors and other examples of situations that indicate that "sameness" might not always be the most desirable of arrangements.