The huge assumption that Nathan makes here is that "problems I have" can always be extended to "problems that a profitable target market has." You're surely ri

The huge assumption that Nathan makes here is that "problems I have" can always be extended to "problems that a profitable target market has." You're surely right that that assumption is invalid, but I don't think he is making it. He's saying that if you operate from "problems I have", you're in a much stronger position than if you rely on external feedback alone. Both your point and his can be true. Of course, the two add up to a big problem—but that's because this stuff is hard. There's no system for making it easier.