There are a lot of good answers here -- the risks of innovation, the necessity of hiring well, etc. I think the core of this is that everyone in a first-time entrepreneurial effort is going to have their own blindspots. Here is one way I've explained this to people since my own first software effort:

An idea is not a design
A design is not a prototype
A prototype is not a program
A program is not a product
A product is not a business
A business is not profits
Profits are not an exit
And an exit is not happiness.

There are new skills and new lessons at each of those turns, dealing with team creation, product management, etc. Each of those needs to be done well, and the skills that make you good at one leave you vulnerable in the other areas.

The real wisdom of entrepreneurship is to know what you do well and to value rather than disdain what others do that you don't.