A HaHaOnlySerious joke is not meant to represent absolute truth, but to be truthful enough to provoke reflection on the subject.
In this case, I am suggesting that if you survey some large group of Canadians, and 58% admit to peeing in a pool, there is also some non-trivial number of Canadians surveyed who have peed in a pool, but will not admit it to you.
I didn't know a single person on the swim team in high school who didn't pee in the pool. Now they're not exactly "adults" technically, but neither are they children.
