My Grandfather alav hashalom, was not Jewish either.

The offices of the Jewish Federation called a certain guy for a donation and he answered the phone in a thick British accent and an imperious tone, and he said "Madam, there must be a mistake. My name is Oliver Andrew Hamilton the Third and I'm not Jewish." And with that he hung up.
The next day, his card got put in the wrong pile and he was called again, and he said the same thing. "Young lady, there must be some mistake. My name is Oliver Andrew Hamilton the Third and I am not Jewish." The next day, his card got put in the wrong pile again, and this time he really blew up.
"Madam, there must be some mistake," he said. "My name is Oliver Andrew Hamilton the Third, and I am not Jewish. And my father Oliver Andrew Hamilton the Second is also not Jewish, and my grandfather, Oliver Andrew Hamilton the First, alav hashalom, was not Jewish either."