Confidence and Winning

How does one maintain an abundance of self-confidence?

Confidence and self assurredness comes and goes like an earthquake. Self doubt creeps up on you and before you know it everything is a mess. You never saw it coming but the after affects are tremendous.

Why are some people successful in achieving their goals while others are not?

Is it because winners keep trying regardless of the obstacles they face or the roadblocks they encounter while losers give up as soon as the road becomes difficult?

I have realized that everyone experiences moments of insecurity but what separates the winners from the pack is that they surround themselves with a network of encouraging people and will readily say an affirmation before that earthquake of self doubt begins rumbling.