Let me out," Harry said again.
"No," Dumbledore repeated.
"If you don't - if you keep me in here - if you don't let me-"
"By all means continue destroying my possessions," said Dumbledore. "I daresay I have too many.

Of course we still want to know you!" Harry said, staring at Hagrid.
"You don't think anything that Skeeter cow - sorry, Professor," he added quickly, looking at Dumbledore.
"I have gone temporarily deaf and haven't any idea what you said, Harry," said Dumbledore, twiddling his thumbs and staring at the ceiling.

I thought it sounded a bit like Percy singing... maybe you've got to attack him while he's in the shower, Harry.

We're coming or you whether the Muggles like it or not, you can't miss the World Cup, only Mum and Dad reckon it's better if we pretend to ask their permission first. If they say yes, send Pig back with your answer pronto, and we'll come and get you at five o'clock on Sunday. If they say no, send Pig back pronto and we'll come and get you at five o'clock on Sunday anyway.

Gilderoy Lockhart, Order of Merlin, Third Class, Honorary Member of the Dark Force Defense League, and five times winner of Witch Weekly's Most Charming Smile Award. But I don't talk about that; I didn't get rid of the Banden Banshee by smiling at him.

I suspect Nargles are behind it.