Who are you?

One of my all time favorite movie scenes is from Alice in Wonderland, where the Caterpillar asks Alice, "Whooooo R U"? and Alice replies, "I hardly know, sir. I've changed so many times since this morning..." I'm not sure if it is the question or the answer that resonates so soundly with me.

I've been pondering the question of late. The obvious answer of: "we are what we do" comes to mind. But, that can't be the whole story.