Well... maybe the closest thing that I am an "expert" in is literature.
Saying this because whenever I play a quiz game together with some people that I know, I very often get the literature questions correct.
But I have also read many books, including non-fiction books about literature.
And then I have also watched Youtube videos and stuff, where they talk about literature.
I don't think that I could call myself a literature expert because I feel like there are people who know much more about literature than I do.