Through The Looking Glass:

"And who are you?"

This was not an encouraging opening for a conversation.

"I - I hardly know sir, just at present at least I know who I was when I got up this morning, but I think I must have been changed several times since then."

"What do you mean by that?  Explain yourself!"

"I can't explain myself I'm afraid, sir, because I'm not myself, you see."

"I don't see."

"I'm afraid I can't put it more clearly, for I can't understand it myself to begin with."