Your older brother always came home really late, meaning he was never there to supervise you or help you study. So you didn’t. You could usually get away with a few D’s from time to time and majority C’s but coming home with straight fails would definitely get you in trouble. So you hid your results from him. Until one day you woke up to him waving your test paper in your face

“Care to explain this?”

Your assumption about his observance was proven wrong once he pulled that out. You hid it really well too