I believe that the "10% of our brains" expression is simply just that, an expression. I only used it to demonstrate that the brain can do incredible things, ie. instaneously calculate the trajectory of a ball in flight.
Try to do it on paper. Chances are, the ball will hit you before your pen hits the pad.
You can utilize this brain power not only to catch balls, but eventually it can be used in budo. Then you will see some progress to your art!