A bedtime story is read as comfort, safety and the stories that shaped you. Dream books link it to a wish to be soothed, or to reflect on the tales you tell yourself.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.