As a young lad prepares to go on his first date, his father gives him the following advice: "If you are ever stuck for a topic of conversation, just remember the three foolproof openers : food, family, and philosophy. You can always initiate a lively conversation about any one of those subjects."
He collects his lady-friend from her house and they go to the pictures. Queuing for seats, there’s a long uncomfortable silence and the lad's nervousness builds. Remembering his father's advice, he asks the girl: "Do you like potato pancakes?" She says "No," and the silence returns.
After a few more uncomfortable minutes, he turns to the second item on the list. He asks, "Do you have a brother?" The girl says "No," and silence once again envelopes the nervous couple.
The boy then plays his last card. He thinks of his father's advice and blurts out: "If you had a brother, would he like potato pancakes?"