Me : Everyone and no-one. It's not a single person, it's an amalgam of conversations (often multiple) that I have had. It's simply a way of repeating a conversation without creating a fake persona by being clear it's not anyone.
Me : It's quite common to see people creating a whole bunch of fake twitter accounts and then have a "conversation" with them in order to prove some point which is normally how wonderful they are or some other self - sycophantic / self adulation gone mad.
Me : Thanks Mum.
X : I agree with your Mum.
Me : Thanks Dad.
X : Was that really your mother?
Me : No, that's the point, X is not anyone. Oh, and yes I can be a real ass sometimes.
Me : Oh, she has definitely told me that and been right on every occasion. I use real stories / conversations behind X but as I said, X isn't anyone.