How funny it is to make up something patently ridiculous, attribute it to someone else
But Piglet didn't, as we can all see. S/he did not make up the fact that you said that the foreskin retains urine. S/he then, correctly, pointed out that you were thus asserting that it is a container that fills up with urine. S/he didn't make it up, or lie, or attribute it incorrectly. And, no matter how many times you aggressively deny that, we can all see the truth for ourselves.
And the idea that circumcision is the equivalent of vaccination is utterly ludicrous.
HPV is a known risk factor for penile cancer and is itself a disease one would wish to avoid by whatever means one could.
Clearly millions of parents don't agree with that proposition. Given the fact that penile cancer rates are lower in Europe than in the US despite the higher circumcision rate in the US, it's hardly a certain way of avoiding penile cancer. And how many parents, presented with, on the one hand, the bare possibility of penile cancer (which can be eliminated by proper washing) and, on the other hand, the higher chance of death, would opt for the latter?