McLaggen makes Grawp look like a gentleman.

I remember every wand I’ve ever sold, Mr. Potter. Every single wand. It so happens that the phoenix whose tail feather is in your wand, gave another feather — just one other. It is very curious indeed that you should be destined for this wand when its brother — why, its brother gave you that scar.

This exchange marked the beginning of Mr. Malfoy's long campaign to have me removed from my post as headmaster of Hogwarts, and of mine to have him removed from his position as Lord Voldemort's Favorite Death Eater. My response prompted several further letters from Mr. Malfoy, but as they consisted mainly of opprobrious remarks on my sanity, parentage, and hygiene, their relevance to this commentary is remote.

Her voice was now so shrill only bats would be able to hear it soon, but she had reached a level of indignation that rendered her temporarily speechless.

I'm interested in that drive, that rush to judgment, that is so prevalent in our society.We all know that pleasurable rush that comes from condemning, and in the short term it's quite a satisfying thing to do, isn't it?

The dementors send their love, Potter!

How do you remember everything from different books when you are still writing the HP series? As obsessive fans will tell you, I do slip up! Several classrooms move floors mysteriously between books and these are the least serious continuity errors! Most of the fansites will point you in the direction of my mistakes. But the essentials remain consistent from book to book because the story has been plotted for a long time and it is clear in my mind.