Credibility grows when you resist pretending to know what you do not.

There is a strong pull to produce an answer, especially when being asked in front of others. Resisting it feels like losing status, and it does the opposite over any meaningful stretch of time. People discover eventually which answers were invented, and once they have, everything else gets checked. Saying you do not know is a short-term cost and a long-term deposit.

Have a phrase ready for the moment, something simple about not knowing and finding out. Use it once this week where you would normally guess. Then follow up with the real answer.