I would echo lynneiha, I did well achademically, but struggled hard to concentrate at school. ADHD gives you a hyperfocus and mine locked onto study. But I also struggled to keep menial jobs yet did well in management once I had a PA to keep a diary and such. You can’t take a simplistic view, such as “You must have done badly at school to have ADHD” that’s lazy. I was put on detention for not focusing or being impulsive and yet got mostly grade A’s I was also considered well mannered, so surprised many that I kept getting into trouble. lol. That did confuse the teachers that liked to label you and pop you in a box.