Because you are so obviously a Ravenclaw! Poppa (resident Slytherin) might be a Parselmouth, but PAA?
That isn’t like Percy at all to bluff. It is like him to think he could, but more like him to think he should. Hmmm. I prefer my answer!
Just thinking now, the point system is quite nonproportionate too. At the beginning of Book 1, we start by docking one point at a time. After that, the numbers seem to multiply!