Well ADHD is not a lack of attention but a lack of control over your attention. And yeah, when I was really obsessed with something, I would spend the entire day doing it, and then the rest of the days until it lost its charm or I finished whatever I had planned. I always binge YT, anime, movies, manga, books. It's very hard to pry yourself off of them once you start. Sometimes it's just easier to finish it, but just don't dare start anything else because then you're back at the start.