“Who are you?” said the Caterpillar.
This was not an encouraging opening for a conversation. Alice replied, rather shyly, “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?” said the Caterpillar, sternly. “Explain yourself!”
“I ca’n’t explain myself, I’m afraid, Sir,” said Alice, “because I am not myself, you see.”

― Lewis Carroll Tweet