First sign of madness, talking to your own head.

To Harry Potter — the boy who lived!

I will if you go out with me, Evans

The truth. It is a beautiful and terrible thing, and must therefore be treated with great caution.

If you have to ask, you’ll never know. If you know, you need only ask.

Why can’t I drink the potion instead?” asked Harry desperately. “Because I am much older, much cleverer, and much less valuable,” said Dumbledore.

Odd words floated back to them over the hundreds of heads. "Nobility of spirit"..."intellectual contribution"..."greatness of heart"...It did not mean very much. It had little to do with Dumbledore as Harry had known him. He suddenly remembered Dumbledore's idea of a few words, "nitwit," "oddment," "blubber," and "tweak," and again had to suppress a grin.