The enemies of practice are pride and fear and self-satisfaction.
To practice requires humility. It forces us to admit that we don't know everything.
It forces us to submit to feedback from people who can teach us. But surely practice isn't a sign if weakness — after all, some of the people most famously disciplined about practice are Michael Jordan, Jerry Rice, Roger Federer, Mia Hamm, and Tiger Woods.
To practice isn't to declare, I'm bad.
To practice is to declare, I can be better.
— taken from Practice Perfect, by Doug Lemov