I think too many business people are afraid of being wrong in their decisions that they often do not pursue ideas or dreams because of that fear. However, in business you do not have to be right all the time, but you have to be brave enough to try new things. If feel that many times business people decide to take too long to cultivate the "perfect plan" rather then taking a little risk to go with an initial plan and tweaking it as necessary. This quote from a Blog Maverick post by Mark Cuban pretty much sums it up well:
"In Business, the odds are a little different. You don’t have to break the Mendoza line (hitting .200). In fact, it doesn't matter how many times you strike out. In business, to be a success, you only have to be right once."
While I understand the importance of business models and planning, I think Mark Cuban has it right when it comes to being successful in business. To read his full post check out his Blog Maverick on Success and Motivation. Also check some blogosphere perspectives on Mark's post on Paul Explains Everything and Thoughts from a Management Lawyer.