Related:

• You know what they say about paradigms - shift happens!
• Do you know what you're talking about?
• It isn't what they say about you, it's what they whisper. -- Errol Fly
• You know what they say - don't get mad, get angry...
• I often say that when you can measure what you are speaking about, and express it in numbers, you know something about i
  but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind...
• You don't know what you're talking about, do you?
• Say what you know, do what you must, come what may.
• You don't expect me to know what to say about a play when I don't know who the author is, do you?
  ...If it's by a good author, it's a good play, naturally....
• If someone told me it wasn't "fashionable" to talk about freedom, I think I'd just have to look him square in the eye and say, "Okay, YOU TELL ME what's `fashionable'.
  But he won't. And you know why? Because you can't ask someone what's fashionable in a smart-alecky way like that....