Circus is a dance with failure. The performers who train every day to soar through the air on trapeze have fallen many times, so that when the time comes to do it for an audience, they'll hit their mark.
Niels Bohr said, "An expert is a man who has made all the mistakes which can be made, in a narrow field."
The path to mastery, therefore, is simply to make all the mistakes, and learn from them.
But even the best mess up sometimes, especially if you're trying to accomplish something as difficult as most circus tricks.
A good juggler understands this. They'll tell you that a dropped ball or club is simply an opportunity for another trick. They've practiced making mistakes.
But Ricky, one of the Flying Wallendas who famously don't use a net when walking across the tightwire says, "There's no way to practice falling from 30 feet." Having a net, they argue, makes falling more likely, because it makes you overconfident.
But still, the Wallendas do practice falling from shorter heights.
That way, when they step out on the high wire, they can clear their mind and concentrate, confident in their thousands of hours of preparation.
But not too confident.