Not countries that you hate, but that you really feel absolutely nothing about one way or the other, and that you only think of when you're reminded they exist.
Spain and Portugal for me.
Like, when I try to read Spanish history, my mind starts to wander or I get incredibly tired, and I LOVE foreign history. You'd think that with all the wild factions of the Spanish Civil War that I could pay attention, but the fact it takes place in Spain just makes me unable to maintain interest.
I genuinely forget that Spain and Spanish people exist to the point where often times when I refer to the Spanish language, I find myself subconsciously calling it "Mexican" instead of "Spanish," since Mexico at least has proximity.
Even though one of my favorite horror movies, Rec 2, is Spanish, I almost always forget. It just takes place in a "foreign country" in my mind and I rarely ever ponder which country, likely because my subconscious knows it's Spain and that I'll forget after anyway.
Portugal is much the same. I'm interested in Cold War African conflicts, but all the ones in Portuguese colonies just bore me to death, at least until the Portuguese leave.
The only time I remember Spain or Portugal is when it's brought up directly, when I decide to purposefully try and recall countries I have no interest in, or when I think of Vagrant Holiday,
https://www.youtube.com/watch?v=qr5jQpO8JZw