You don't have to have all the answers. No one, no matter how smart they are, can be that good. But by empowering people so that they have the freedom to be creative, and the leeway to make mistakes, the team as a whole will end up better off. Great managers, I think, refine and enable greatness. Sure, it's good to have an awesome idea and move forward with it, but it's more important to inspire, than try to take all the credit.