As usual, I was in Spain on April 1st. The only people around here who have heard of April Fool's Day are expats. In northern Spain (about 1200 miles from here), near the French border, some people (a minority) have heard of it (and play tricks whose victims are "pescados de Abril" if they fall for them; but for some incomprehensible reason are not "peces de Abril" if they aren't caught) but even there, it's not like it is in the USA and other countries where the April Fool's Day tradition is live. Here it is 28th December instead of 1st April.

So it's still true that all the humour questions have a particular cultural bias. I suppose that's inevitable though.