Saying “I don’t get it” when everyone else is laughing takes more confidence than fake laughing ever will.

Fake laughing is the cheaper move in the moment and the more expensive one afterward. Admitting you missed something puts you briefly outside the group, which is exactly why it takes nerve, and it is also how you learn that several other people were doing the same math. Confidence is not knowing everything; it is being able to be visibly behind for a second. The pretending is what actually costs you.

Say it once this week, lightly, with no apology attached. You will usually get an explanation, and sometimes a quiet thank you from the person beside you.