I think I've already named a post that, but I can't remember..... (~~~~censored and deleted~~~~) Why am I telling you all this...? I literally sat at my computer for 4 and a half minutes trying to think of a good explination, but none came to mind so I will go and delete that from my post...... but then you wouldn't know what I was talking about.... too late.

Why IS a raven like a writing desk?

   Because it can produce few notes, of which are very flat, and never has the wrong end in front.