I don't know if he still does it because I stopped watching a long time ago, but here in the US, Jay Leno of the Tonight Show did a similar comedy bit, called JayWalking, where he has someone ask random people on the street common-knowledge questions.

So, here in the US, a lot of people have seen that bit and understand how it works: give correct answers and get edited out of the clip; give wrong answers, especially funny ones, and you get your 15 seconds of fame.

Also, some of those people, just didn't seem like they were really trying.