the ones who achieve "success" are the best at deluding themselves or best at staying ignorant. when faced with reality, a well-informed, rational person can not help but weigh the odds of success and to rationalize a lesser course as more suitable. the rational person will see the slim odds of success and not even bother at an attempt. it is the human that deludes himself into a world of fantasy, or ignorance, that takes the risks towards success.

from a different perspective, you can purposely use delusion to help yourself achieve goals you otherwise thought impossible. you can talk yourself into doing a lot of things and achieving more. start small to prove it to yourself and work your way up to the bigger things.