Question: Can you explain your joke?

Aimé Fournier answered on 9 Jun 2011:

No one ever asked me that before, and I’ve told that joke dozens of times since I first heard it in 1989, always evoking great laughter (except from one Swiss friend of mine). I can explain it but then it wouldn’t be funny anymore. Like many jokes, this one relies a bit on stereotypes and reputations, and isn’t spiritually generous. At least, it should seem to be equally generous and offensive to five nationalities!