If one fails and one tries again, one will make course corrections. Keep repeating that cycle, and one is bound to home in on success.
Psychologically, I think juggling is a fantastic skill to practice because one must fail a million times and keep going. Furthermore, one must learn to choose failure over a spastic success (and condition that behavior in on the fly.) By this I mean, one must learn to let the ball drop rather than lunging to make a frantic catch, because if you are always making wild reaches, you’ll never achieve a smooth, natural rhythm. In other words, a catch that keeps the ball in the air for one or two more throws is not truly a success if it trains a wobbly, unsustainable movement pattern. More generally, one must redefine what constitutes success or failure at a fundamental level.
Tiger Riding for Beginners 