The Glabella Indicates Dislike
The worry of speaking the incorrect thing is something that almost everyone has experienced. The good news is that you can now reasonably determine whether someone thinks what you're saying is stupid. We often crease our glabella when we hear something that we don't like because we believe it to be stupid, incorrect, or in some other way unpleasant. That is the area at the peak of your nose, directly between your eyes. Watch what you say as that tiny patch starts to wrinkle. The individual you're speaking to is not at all engaged in the conversation if it keeps happening. There's a strong probability they don't like you, or at least what you're saying, even if they might still be nice.