To get off the couch and do something interesting requires confidence. The more interesting the thing, the more confidence you need. But if you have too much confidence, you’ll be blind to the lessons you need to learn to make something as good as what you imagined in your mind.
But if you have too little confidence, you either won’t get off the couch, or you’ll give up when you hit your first wall. And no interesting thing is finished without hitting some walls.
The paradox is to be confident, but not confident. Or to posses the self-control to make yourself confident, or doubtful, whenever you wish, mastering the tightrope of your own mind.
People who make good things walk this tightrope all the time.