“Hogwarts, Hogwarts, Hoggy Warty Hogwarts,
Teach us something please,
Whether we be old and bald,
Or young with scabby knees,
Our heads could do with filling
With some interesting stuff,
For now they're bare and full of air,
Dead flies and bits of fluff,
So teach us something worth knowing,
Bring us back what we've forgot,
Just do your best, we'll do the rest,
And learn until our brains all rot...”

What happened down in the dungeons between you and Professor Quirrell is a complete secret, so, naturally the whole school knows.

“The truth." Dumbledore sighed. "It is a beautiful and terrible thing, and should therefore be treated with great caution.”

It takes a great deal of bravery to stand up to our enemies, but just as much to stand up to our friends.