Unintended consequences, he thought miserably. He was angry at his anger, the way it surged up and took over.

The trouble with anger is, it gets hold of you. And then you aren't the master of yourself anymore. Anger is. And when anger is the boss, you get unintended consequences.

People find a way through just about anything.

Doon was touched. Kenny looked like a tiny little wisp, but there was something strong inside him. --People of Sparks--

Now Doon seemed to care for his new friends more than he did for her. Every time she thought about him she felt a thud of pain, like a bruised place inside her.

She realized all at once that Doon, thin, dark eyed Doon, with his troublesome temper and his terrible brown jacket, and his good heart---- was the person she knew better than anyone now. He was her best friend. --City of Ember--

The main thing to do is pay attention. Pay close attention to everything, notice what no one else notices. Then you'll know what no one else knows, and that's always useful.