The personal qualities necessary for success can be nurtured. In time, the personal qualities will fully develop.
The main benefit of optimism is resilience in the face of setbacks
We need to have full confidence in our judgement about a company if we are to make a serious financial commitment to it. But, the strength of our belief that we are right has nothing to do with the validity of our judgement. And, if that sounds weird, blame in on behavioral psychology.