You can't afford to follow this advice. Saying you're crushing it is part of your 24/7 job description.

There is a story of the founder who had just put a round together with a VC. Then, privately, the founder confided to a mutual friend, over dinner, about some of the difficulties. Result? The friend told the VC, the VC pulled out, and cited this conversation, saying that it was because his mutual friend said the company was having difficulties.

You can't afford to talk.