From Seth's Blog:
"Do you know enough?
If not, what are you doing about it?
If so, who do you think you're kidding?
[Interesting side alley: I was talking to a friend yesterday and encouraged her to speak at an upcoming conference. She said, "No way. I don't know enough." I explained that volunteering to speak was the best way to be sure that she'd end up knowing enough by the time she was through.]"
Interesting dilemma. Have broad knowledge, or be specific. In a world where most things are becoming commodities, what are you doing to become outstanding in your field? On the flip side, from The Incredibles: "If everyone is special, then no one will be."
What is an "Expert"? Someone who knows more about a subject matter than you. Sometimes we require certification to justify the "Expert" title- degrees, initials, published materials, etc. Convincing people you're an SME shouldn't be hard. Just let others handle things without you. It will let them, and you, know how much of an "expert" you are.