One can be a "master carpenter", yet not every corner will always be smooth. One can be a "master sailor" ... but had best watch out for the next storm. One can be a master lion tamer ... but it is just lion by lion by lion, step by step by step. A "master surgeon" cannot cure every patient, and even the most gifted may sometimes make a bad cut.
Mastery does not mean that one will never fall down.
On the other hand, turning most of one's woodwork to splinters and sawdust, sinking boat after boat, and abusing the lions or negligently butchering patients ... that is -not-
In fact, in the martial arts, there is no "Wu Shu master" who never falls ... but endless masters who know to fall well, roll with the forces, recover their feet, move ahead. The true "mastery" is rolling with/as/though what is thrown at one ... stillness in motion (as in the martial arts ... there is no training offered on how to never fall, but endless training on how to fall well
). Show me the man or woman who falls down sometimes ... but who demonstrates how to fall well and recover one's footing ... and I will show you a great Zen "Master".