Saying "no" can keep you from succeeding, but "yes" can take you closer to achievement. You've worked with those folks before -- the "no" people. The "no" people are good at pointing out the obstacles to getting good things done, but they seldom have any ideas for solutions. They are closely related to the "yes, but" people. Stellar employees and colleagues are "yes" people. They realistically acknowledge the challenges before them, and then they get creative and figure out how to work around those challenges so that the entire team can progress and customers get the best service possible. As Abraham Lincoln once said, "Determine that the thing can and shall be done, and then we shall find the way."