As a start up founder you need both Realism (getting to the cold truth of your sales prospects) and Positive Creativity (imagining a bright future for your product).
Both perspectives are important. Realism keeps you grounded and forces you to compensate for deals that will fall through. Positive Creativity leverages your most powerful tool, your imagination to build a great vision of the future!
Too much realism you get depressed. Nobody buys from someone who is negative.
Too much Positive Creativity and you are just dreaming!
Although these perspectives are contradictory, if you harness their power it will help you build a successful sales engine for your startup.