Percy already had a headache from working all day, and his nephew's obstinate behavior only served to make it worse.
"No one remembers how many I had, dear," he said smartly. "Because OWLs are not a predictor of performance outside Hogwarts. If you want to make a meaningful contribution to society, Alex, you'll need to concern yourself with more than just hair dye and eye liner. When I was your age, I was writing treatises for international relations."
Percy shrugged. "Or you can work in Knockturn Alley. It really is your choice."