In a way, this is yet another derivative of Dunning-Kruger IMO. It's all derived from either: (1) overestimating one's abilities (esp. when transferring from one domain to another), or (2) the corollary of underestimating the difficult/complexity of a given problem because you think you already have enough skills/expertise/resources to tackle it based on your prior successes.

- "I'm a rich/powerful/successful media person. I had success in my industry doing business a certain way, so why shouldn't I be able to translate that into running a tech startup too?"

- "I'm a good programmer and I don't see any reason why Zuckerberg would be smarter than me. What's so special about Facebook? We can beat them."

- "I'm in touch with what most people want, and this product idea totally makes sense to me. All I need to do is polish it up, and I'm sure I'll find users who are as excited about it as I am."

Or, the flip side of the same coin is really about ego. One of the hardest lessons of the lean/agile/tech-y start-up culture (in its idealized form), is to not let ego interfere with learning, but also to be able to let go of ego-centrism without giving up confidence or competence (i.e. you don't have all the answers and you should be fundamentally humble and curious, BUT you should not forget or overlook your existing skills or competencies either).