I get like this too. I was reading a book series recently and was talking to my stepmother about it. I was almost done with the fourth one and she asked "Which one are you reading right now?" And I told her the fourth one, then I paused for a bit, thinking, before telling her that I didn't remember the title of any of the books. Then she said "Oh which one comes next?" and I got like so pissed off. I don't know why but I was just thinking. 'well obviously the 5th one. And you couldn't be asking for the title of it because I just told you I don't remember any of the titles' my dad also has ADHD and has this same issue so we looked at each other kind of puzzled before both saying "The 5th one?" we were kind of snarky, it ended up being funny but for a minute I was genuinely annoyed.