I must misunderstand
A fancy way of saying you think the person talking is a complete idiot.
I must misunderstand. You said the project was on track. It’s three days late, and the client is screaming.
I must misunderstand. You think I’m supposed to laugh at your joke? I’ve been crying since Tuesday.
I must misunderstand. You said the cake was ready. I’ve been waiting for it since 8 a. m.
xs