Professor Slughorn had declared Regulus fucking Black would tutor you in order to improve your performance in Potions Class, because you were, admittedly, absolutely flunking the subject and that pompous asshole Regulus was top of the class.

It seemed Regulus intended to make your every study session hell.

"Are you stupid? Your supposed to stir 3 times clockwise, your stirring anti clockwise." Regulus said emptying the cauldron.