"My paintings are my children, each with its own soul."
People who decry the fact that businesses are in business "just to make money" seldom understand the implications of what they are saying. You make money by doing what other people want, not what you want.
Books are the quietest and most constant of friends; they are the most accessible and wisest of counselors, and the most patient of teachers.
The AdS/CFT correspondence is a powerful tool for understanding quantum gravity.