If you want to test yourself on this, I recommend finding a bar near you that does a trivia night. Bring a couple friends and see how it goes. After a few nights, you'll start to get a feel for how much expertise you have in a variety of topics.

Of course, I maybe only bring that up because that's something I am objectively good at: "Useless" trivia.

Apart from all this road shit, though, I consider myself strong in categories like...
geology
history
geography in general (not just road shit)
evolutionary biology
I could probably be your fishing guide for the upper Mississippi/Western Great Lakes/southern Hudson Bay drainages.
My pop culture expertise slants toward the sci-fi, Next Generation-era Star Trek in particular, and then just a random shot gun blast of shit heavily influenced by references in prime time animation like The Simpsons, South Park, Rick & Morty, Family Guy, etc. Like for example, I saw a huge number of references to Citizen Kane through the lens of Springfield before I ever saw the movie itself.
I will also claim above average competence in some elements of human psychology, especially as it relates to how we delude ourselves or misinterpret the world around us. SectorZ mentions the Dunning-Kruger Effect, and that's just one of the many cognitive biases and shortcomings I am well-versed in. Not enough to always not fall into them myself, mind you, but enough to recognize when groups of people are being deluded by them, most of the time. And when it's obvious, it's super frustrating. Like how do you not call people "stupid" when they are so obviously falling the most basic logical tests for what comes out of their mouths or fingers? But that's a huge digression that only applies to this community on rare occasions.
