Never act like the smartest person in the room
Sometimes it pays to shut up! Especially when you are really smart.
As a bright and capable performer, you will have plenty of opportunities to show what you know and how you know it but one thing you can never do is — show off! People in power don’t like it and people you work with find it annoying.
Smart people who know when to speak up and when to act on their initiatives are a special breed. Don’t squander your opportunities by showing off. Let your cool demeanor speak for you.