Specifically cat urine, not other urine? I must be thankfully smell-deficient because I wouldn't be able to tell the difference, and I grew up with cats for 20 years
We travels in Italy and our budget was low (6 weeks at $30 euros a day). We stayed at camp grounds most of the time. It was good, except they often had cat colony's nearby. The smell was horrific and traveled a long way. It put me off cats in such a big way that 10ish years later I still don't like them.
"Growing up with cats" is a disadvantage in this case - people don't really notice the 'default' environment that they're used to, your nose 'turns off' that specific smell and doesn't record it. My relatives who have cats (especially in the plural) are unable to distuinguish their own items that smell of cat from similar items that don't.
It's similar for smoking - nonsmokers can easily identify traces of smoke smell (like, this particular jacket was worn recently to a place where people smoked) that are not noticeable by the smoker itself.
This is a good point, and one I hadn't thought of. But I wasn't smelling cat pee often either.
If we had two sets of items, one of which we had some cats pee on, and one of which we had some humans pee on, you think you could sort them into cat/human groups with a high degree of success?