One of the curious properties of language is its relation to how we think. The vocabulary we have places rough limits on what we think about. Even the grammar of a language helps structure how we think. (Grammar actually varies widely between different languages). Take the word taco for an example. The word taco is going to represent a variety of different, but similar things to the person who hears it. For an American it may take the form of pieces of meat, cheese, sour cream, and lettuce inside a folded tortilla. Would you have created a taco without hearing the word? Probably not, but if you did the likely hood that it would spread to become a worldwide food is unlikely. However the word alone will now introduce you to a wonderfully variegated culinary delicacy. It may be just a four letter word, but it carries with it a world of creative cooking that you probably would not have experienced had you never heard of the word.
The same happens with ideas. Our knowledge of words usually limits the ideas we will think about. Who knows how many unique ideas we have had that we have simply assumed to be the same as a word that already exists. Occasionally, someone will recognize something as an entirely new concept which is poorly represented by the already existing words. One solution is to redefine a word that already exists. C.S. Lewis takes the word joy and gives it an entirely new meaning in his book Surprised by Joy. Another way is to invent an entirely a word, like Tolkien inventing the word “eucatastrophic.” If this doesn’t happen it is unlikely that the new idea will be passed on. Of course if you invent a physical object, like a computer, or discover a new type of animal, a new word will be inevitable. In your hubris you could also steal a word from another language like Greek or Latin.
Now this is where stories come in and their relationship to words. Stories have the power to explain where words are lacking. Modern people tend to think of it the other way around. You tell stories to illustrate words. Instead I think words are developed as a simplification of stories. Let me give an example.
God could have chosen instead to give us a systematic theology which uses bullet points to describes how to be saved and exactly how it work. Instead he gave us a book which is composed mostly of stories that tell the same thing. It is the work of theologians to take those stories and turn them into systematic theologies. It is also up to them to create words to describe what is going on. For the process of Jesus taking the punishment for our sins and transmitting his righteousness to us they have invented the word penal substitutionary atonement. Because it is man-made the word will have to be a condensing of what actually happened and its use will always be up for debate.
This property of stories which I have no word to describe is valuable for children. Children usually lack the ability to talk about things which they still have the ability to understand, for example their emotions. A child may not be able to express the anxiety or fear they are feeling. However, they will be able to connect those emotions with a monster in a story. A story in which a hero conquers a monster allows a child to work out their fears on their level. In this way stories function as the language of children, expressing ideas and concepts which they do not have the vocabulary and ability to express. Fantasy stories, as they are one step removed from reality, provide safe places for children to be able work out ideas and things they are going through. Few child who have a parent that yells at them every day are going to want to read a story about a child in the same situation who over comes it. It is too fresh and close. However, they might be willing to read a story about a boy who tames a grumpy dragon. The story provides an imaginary world in which to process what is going on, instead of holding the pain inside is. In addition it provides a temporary escape or vacation from a painful reality. Obviously this complex process is going on unconsciously as they read a story. It is only a guess, but I have a feeling that there are a few adults who work like this too.