The child is usually an eager listener. We share a gift of the mind. Suddenly, we are not enforcing rules or teaching lessons. We are stimulating the imagination in an enjoyable way. Language becomes a tool for sharing experience.
Fascination gains precedence over practicality.
We share with delight, not with determination to instruct. We may broaden our range of expression beyond what's accepted in the workaday world. We may become silly, make animal sounds, or act out the behavior of the hulking, slobbering giant. In our mutual enjoyment of the story, we may even become vulnerable. I doubt it.