With practice you'll come to a point of competence. You'll find yourself accomplishing your goals gracefully and confidently.
It's then that you'll do things that you never dreamed you could do. You'll discover powers you never knew existed. If you're prepared, you're able to feel confident.
There can be no great courage when there is no confidence or assurance. Half the battle is in the conviction that you can accomplish what you undertake.
Confidence doesn't come out of nowhere. It's the result of constant work and dedication.