I look at it like I'd look upon any hobby. I think that some people (many?) can learn, practice & develop the skills necessary to find these subtle differences, leading maybe to a greater appreciation of them over time. I think that most people, however, find a flavor (or smell) profile they like and kind of stick to that throughout most of their life.

I've found I can now differentiate between certain things like tasting notes after a lifetime of drinking a certain beverage. But yeah, it took close to a decade of doing it and it's also because I really appreciate and enjoy what it is I'm drinking. If you're kind of "meh" to whatever it is you're drinking (or smelling), I don't think you'd have much incentive or interest in developing what constitutes "oakiness" in a wine, for instance.

It's just like a really good musician can hear when someone plays or sings a bad note or something off-key. It's a hobby interest that people develop the skills necessary to enjoy it fully.

If you're just an occasional enjoyer of the same thing, you're not necessarily ever going to have the same experience in order to describe or enjoy it the way the hobbyist does. And there's absolutely nothing wrong with that when you look at it as though it were a hobby. It's just a hobby you don't have any particular interest in other than occasionally enjoying.