What is the most common mistake entrepreneurs make when completing their business plan?

For a survey of venture capitalists, see: http://www.capital-connection.com/survey-common.html. By far the most frequently mentioned mistake was saying that the company had no competition, or underestimating the strength of competitors (32%). The failure to describe a sustainable competitive advantage was also mentioned by 9%. Not clearly explaining the opportunity was the next most frequently mentioned mistake, by 27%. Following that was the related mistake of having a disorganized, unfocused, or even poor presentation (12%). Miscalculation of market share and market size (9%) were also regarded as frequently seen mistakes, with several respondents saying that they still receive business plans that say, "The total market is $1 billion, if we only get 10% of it, we will be a $100 million company"--without ever explaining how they are going to sell $100 million worth of their product. Respondents also said they commonly see business plans that do not address the risks of a venture, ...  more