When you think big about a task bigger than yourself...
When you think big about a task bigger than yourself, like Paul felt about his ministry, then it gets easier to overcome and deal with your perceived shortcomings. Neurobiologists have found that when we are focused on a task bigger than satisfying our own immediate needs (like Paul was, and like we are when we do something for God and the church or for our community), we activate the executive part of the brain (the pre-frontal cortex) which in turn becomes immersed in the pleasurable brain chemical dopamine (Stefan Klein, The Science of Happiness, pp.35-37, 56-57, 107).