What does it mean?

No,this ain't a thesis on the double rainbow (That shit just cannot be explained).But rather it's about people without comebacks or better responses.
eg 1.
Me:"hey,you are a complete idiot".


Random 1:"what do you mean I'm a complete idiot?".


Honestly,it does not mean that I think you have a gorgeous brow and would love some oreos in your nostrils.It god damn means "you are an idiot"idiot.

eg 2.
Me:"Hey I think the guy you are looking for just left".


Random 2:"What do you mean he left?".


Sigh,I could explain his departure better to you but unfortunately I don't really speak retard.
So stop asking the meaning of statements which can never be questions.
It's stupid.Infact it's more than stupid.
It's a red raccoons butt cream.
So,are you a dead raccoons but cream?....well?
I thought so.