To check whether a phrase is grammatical one should replace a word by another with same gramatical category, and if it continues to make no sense at all then one knows for sure that the answer is, "what the hell am I doing?"

You're making no sense, how does that make you feel?

For example, suppose we substituted "rock" for "buffalo" in the above sentence; what would we learn from that experiment?

What's the purpose of this experiment?

Haven't anyone told you that we are working on a secret mission?

On which mission?

Do you have the need to know?

Why would he not have the right to know?

In what book does need = right?

How to answer all these the Questions?

Do you know all the answers?

Isn't there a dude with all the answers, but he has opted to work at BFL to augment his Navy pension, thus treating said employment as a hobby?

Given that we all know the answer to that question, why do you ask?

Yet why do we bother to ask rhetorical questions?

Do you really expect an answer, or was that just a rhetorical question?

Did you know that the anagram for Rhetorical Question is Cheaters Into Liquor?

Why did you change the subject?