The article Why do entrepreneurs engage in self-sabotage? tells something about human nature which in general applies to everyone, but gets super-exposed when starting a company.
In his 1985 book, Innovation and Entrepreneurship, Drucker relates the story of Alfred Einhorn, who invented Novocain, which then became popular with dentists as a local anesthetic. Einhorn held a contempt for dentistry, since it was such a small market. He felt that Novocain should be used by surgeons for all forms of surgery. General surgery was more prestigious than dentistry, and so Einhorn waged a campaign against the use of Novocain by dentists. In the end, his innovation was successful despite him, rather than because of him. According to Drucker, this pattern, where a product is undercut by the entrepreneur who created it, is extremely common.
In his book, Lucky or Smart, Peabody says it is important to be smart enough to know when you are getting lucky. And then, you have to be willing to accept that luck. This takes humility. What’s needed in an entrepreneur is emotional resilience, the kind of strength that allows a person to show grace when their ideas have been proven wrong. One has to adapt to each surprise.