When you go to work, do you feel that you have something to contribute? Do you feel that your ideas are worth listening to? Do you believe that what you bring to the enterprise is important? Good. Leaders need to feel that they make a positive difference -- but not the only difference. If you believe the former but not the latter you are wise; but if you believe both you may be suffering from the dreaded disease of “importantitis.”

Terry Teachout, drama critic for The Wall Street Journal, attributes that phrase to Stephen Sondheim, who said that Leonard Bernstein had developed a “bad case of importantitis,” which crippled Bernstein’s later career. Teachout argues that when artists become so enamored of their brilliance, it actually hinders the development of their art. The same thing happens in the C-suite. Not all ideas deserve to be turned into projects. Not all offhand comments are catchy slogans.

Because those afflicted with importantitis think everything they contribute is important, they also think everything they do must be important. So they push themselves and their staffs to take unreasonable risks for very little gain.

How can you inoculate yourself against that?

Listen to your people. Self-importantitis, the most virulent strain, prevents two-way communication. Don't do all the talking and none of the listening. Savvy leaders learn early on that good listening leads to good ideas, especially since they come from the people doing the heavy lifting.

Learn from your customers. Spending time with customers, internal or external, will give you insight into how well, or not, your products or services are doing as advertised. If they are up to par, or not, ask for suggestions for improvement. Listen to what your customers tell you.

Surround yourself with jokesters. Andrew Young, former U.S. ambassador to the U.N., has spoken often of the light moments that he and his civil rights colleagues spent with Dr. Martin Luther King Jr. Brotherly pillow fights and verbal razzing were common. Not only did those things lighten the tension, but they helped keep King rooted in reality.

Not everyone who thinks highly of herself or her talents is wrong. Ego is a necessary part of leadership. Without belief in self, one cannot lead someone else. But when ego supersedes common sense, you've got problems. Surround yourself with equally capable and strong-willed people. Give them permission to disagree with you on a regular basis. Infatuation with one’s own brilliance can be hazardous to your ability to lead.

Are you wrestling with importantitis? Is your boss?

John Baldoni is a leadership consultant/coach and speaker as well as the author of six books on the topic.