if you love learning and are good at reading, school can be easy, the rest of life not so much
If you really enjoy your courses and like your profs, you may excel. I had a student who in fourth year, had a perfect 4.0 grade average. Yet, her personal life was a disaster, her apartment a pig sty, her friends frustrated with her, and she was unable to manage a relationship - quickly getting bored if the partner didn't get frustrated first.
Doing well academically may be because somewhere you had good habits drilled into you - parents who made sure homework was done on time, school programmes that taught you how to study.
I talk elsewhere about the ways that some patients with ADHD are very organized, either naturally or to manage their adhd or because anxiety drives them to be organized.
I sometimes see teenagers who have few symptoms of ADHD but it's because of helicopter parents, who watch them like a hawk, who stand over them as they go out the door, checking that they have the right books, and their lunch, and bus money, and the homework the parent helped them complete last night. These often turn out to be students who want to go away for university, far, far away. You can guess how well it works when the supports all disappear.