Know What You Don’t Know
Good advice from Hans Bjordahl:
If there’s one lesson I’ve seen repeated over and over again in the tech field, it’s this: Know what you don’t know.
Follow this simple rule and, at worst, you’ll have to detour a bit to get a clarification or some new information. Bluff your way through, however, and it’s a short, slippery slope to the worst case scenario, with each bluff compounding on the last. Hint: If you’re already leading a 30-person Java implementation, it’s way too late to go back to the boss and admit you picked the technology because you like coffee.
The smartest people I know are the quickest to point out  no matter who else is in the room  when a particular topic or tidbit of knowledge is beyond them. They ask, they clarify, and now they’re just a little bit smarter than when the meeting started. Half the time, they’re asking about something no one else in the room knew either  it’s just that the others were unwilling to speak up and admit it.
Bottom line: Knowledge moves faster than you do. Ask a lot of questions. Only the idiots know everything.