I find it difficult to imagine that the unsuccessful among us somehow started a business thinking "I never want my business to ever make more than $25,000 a year and what's more, I will most likely fail anyway!" Its nonsense, and this is where the statistics come in. You need to take a large enough sample and rate the traits your groups exhibits and at a minimum compute a p value for the hypothesis that trait A, let’s say positive thinking, distinguishes populations X and Y. No one ever does anything remotely like this. So despite the rather silly premise that you can think yourself rich, they don't even bother to try to test their hypotheses.
The fact of the matter is that randomness plays a much higher role in people’s lives than they want to admit. Let’s take the example of new restaurants. You often hear the statistic that 90% of new restaurants fail. It's actually closer to 67%, but that still isn't very good odds. So what is the differentiator? The successful new eateries are usually started as 2ed or 3rd establishments by an already successful chef. The 90% failure rate applies to people who knew nothing about the restaurant business before venturing out into the mean streets.
So is positive thinking what made the restaurants successful? No it was understanding the business. What made the 10% of newbies succeed? Chance.
I'm pretty good at building homology models and using them for virtual screening. I usually listen to Baroque opera while building them. Therefore should you, gentle reader, rush out and purchase a selection of Lully, Campra and Rameau before your next homology modeling exercise? Yes! Not because it will help you build models, but because the music is wonderful and will elevate your spirit. To be successful at the homology modeling game. Build a lot of homology models and learn from your mistakes. Trial and error, not positive thinking is the secret of success.