Lois Lowry's was inspired by her father's memory loss. 

Like so many who've suffered the pain of losing someone, Lowry considered — just passingly — how much better our existences might be if we didn't have memories at all. The idea of a world where nearly everyone takes drugs to suppress their memories and emotions.

"And so I began to think about writing a book about people who had found a way to manipulate human memory, so they wouldn't have to remember anything bad," Lois Lowry explains.