A zebra died and came to heaven. At the doors he met Jesus, and asked: Help me please find out whether i'm white with black stripes or black with white stripes?
Jesus said: That's out of my league, go on in and ask God.
The zebra asked God: What am i? White with black stripes or black with white stripes?
God said: You are what you are!

The zebra went back to Jesus.
Jesus said: What did he tell you?
The zebra said: I can't figure, he said you are what you are!
Jesus said: Then you're white with black stripes.
The zebra: how can you tell from that?
Jesus: If you were black with white stripes he'd say: You is what you is!