The importance of pretend play has long been noted as an important milestone in children's development. Pretend Play allows children to experiment with social situations, strengthen vocabulary and build critical thinking skills. A child who engages in pretend play is also beginning the process of metaphorical thinking.
One cannot think without metaphors. Metaphors are our way of making connections with the rest of the world; it is our way of understanding new ideas and learning. George Lakoff, another of my favorite linguists, explains the concept of metaphor and its relationship to our thinking. But what he doesn't do is talk about the process of becoming metaphorical.
That's where pretend play comes in.