Understanding how we learn new things - be they skills or information - is important.
Learning something new involves moving what we are trying to learn from our short-term memory to our long-term memory. Things can only be held in our short-term memory for a short period of time and if the information or skill is not transferred into our long-term memory we will forget it. The short video above (a great short video to watch with your son) explains the science behind this and reveals why practice is important; doing something once will not move it into our long-term memory, but practice will. Learning how to drive is a prime example of this.