Why do people think I'm funny when they pretend to draw a few pictures in the air with their fingers? I always meet people who treat me like a joke for no reason.

On the one hand, their expressions are too exaggerated. Or they thought of another way. It may not be entirely related to you.

On the other hand, I also remind you that you may have to pay attention to your behavior in public. For example, you can draw on the desktop like this and say, let me do the math.