Most of our lives we learn specifically what we need to achieve our goals. As children, we learn how to crawl, walk, and talk when we are physically ready to do so and when our brains are sufficiently developed to take on the task. Even so, we will only attempt something new, like the precarious act of walking, when we are motivated to do it. Babies start to crawl to get to something that they want, their mother and her milk, for example, a shiny toy, or perhaps something to explore. Similarly, we learn to talk to get what we want.