The Recipe for Success must include the proper proportions of optimism, realism, cynicism and negativism.
You need lots of optimism to dream up all the possibilities of things you can accomplish.
A goodly amount of realism is necessary to help you figure out which of those are the best ones to pursue.
Even a dollop of cynicism is a good thing, because it helps you learn from your mistakes and make better choices.
But even a pinch of negativism puts everything at risk, threatening to instill a bitter taste in all your endeavors. Best to leave it in the cupboard.