In an industry where 1001 questions are asked each and every day, I find myself dealing with people who seem to have an answer for everything. Now I don't claim to be an expert in everything, but hearing people 'um' and 'ahh' their way through answers, or dancing around the question asked is somewhat frustrating.
Some of the best clients and candidates I have ever worked with, I rate so highly because they are not afraid to tell me they don't know something. In a day when we have google, forums and talented networks, I would much rather hear from someone "I don't know, but I would speak to someone in my network to find out".
We live in a nation of 'Yes' men, but the real cream of the crop are the people who say no and ask questions. Next time you don't know the answer to something, put your ego to one side and admit it. Believe it or not, in the long run you will be more successful.