Entrepreneur's reality check

By nature entrepreneurs are positive, which it’s great, that’s what make them succeed more often than not. Nonetheless, that also brings failure. While building a product, entrepreneurs engage at a such deeper level that they no longer can be rational. And that’s an issue.
Too often startups fail because there’s no actual market for their products. And if you mix that with the entrepreneur’s positive nature they’re in big trouble. How can you prevent that to happen to you though? There are too many things to consider here, but an useful way is to ask yourself:
Would you actually pay money for it?
It seems super obvious but if you release yourself from the emotional output, the answer would tell you whether you’re in the right path or not. If the answer is not a hell yeah!, maybe you’re building the wrong product.