Something most strive for in any physical activity, such as playing a set of drums or a guitar. By making sure ones fingers, hands, arms, legs can do different instructions at the same time, people can accomplish tasks that were once thought difficult through repeated practices and "caching" in their muscle memory.
This is as much a brain development issue as well as a physical one. A human brain needs to "understand" its task in the many steps needed to complete it, which typically works from instinct and past experience. One can throw a curveball at the brain by asking it to do things it might not be able to handle at first glance. By working hard to establish independence between various limbs, these tasks become easier and easier.