I read this explaination of confidence today and thought it was perfectly stated.
"Keep in mind confidence is not bravado, or swagger, or an overt pretense of bravery. Confidence is not some bold or brash air of self-belief directed at others. Confidence is quiet. Confidence is a natural expression of ability, expertise, and self-regard."
When I read that, I couldn't help but be reminded about the verse in the Psalms that says, "Be still and know that I am God." Truth be told when I do that, I'm confident, because my focus is on the Lord.