Eventually, as they share a fifth slice of chocolate cake, Lucy says: "Mummy says you and Adolf Hitler have the same birthday. Is that true?"
"That's true, Lucy. Adolf Hitler was very bad man who's dead now. He and I had the same birthday. He would have been 129 today."
"I'm glad Hitler's dead."
Then Lucy says: "Grandpa, are you 129, too?"
Grandpa sighs. "Perhaps. More chocolate cake, Lucy?"